Popular questions and responses by JOHN
  1. math

    In a family with 4 children what is the probability of having 1 boy and then 3 girls, in that order? (Exclude multiple births and assume all outcomes are equally likely). In a family with 4 children, what is the probability of having 1 boy and 3 girls, in

    asked on November 8, 2015
  2. Calculus

    A spinner is used for which it is equally probable that the pointer will land on any one of six regions. Three of the regions are colored red , two are colored green, and one in colored yellow. If the pointer is spun twice, find the probability it will

    asked on December 10, 2007

    A Sample of gas originally at 25 degrees C and 1 atm pressure in a 2.5 L container is allowed to expand until the pressure is .85 atm and the temperature is 15 degrees C. What is the final volume of gas? Did anyone get 2.6 L

    asked on May 12, 2012
  4. math

    Mrs. Richmond bought some apples and pears in the ratio 3:5. After she gave away 3/5 of the apples and 40 pears, the ratio of apples to pears became 2:5. An apple costs 30 cents. A pear costs 15 cents more than an apple. How much did Mrs. Richmond pay for

    asked on July 28, 2014
  5. Calculus

    A stone is dropped from the upper observation deck of a tower, 200 m above the ground. (Assume g = 9.8 m/s^2.) a)Find the distance (in meters) of the stone above ground level at time t. b)With what velocity does it strike the ground? (Round your answer to

    asked on November 13, 2011
  6. Maths

    I can't understand this math problem.... Please help me.... ------------------ Problem: In a boys' school, 5/8 of the boys play football and 4/7 play rugby. If every boy plays at least one of the two games, find the fraction of the boys who play both

    asked on June 30, 2012
  7. Physics

    An elevator in a tall building is allowed to reach a maximum speed of 3.3 m/s going down. What must the tension be in the cable to stop this elevator over a distance of 3.4 m if the elevator has a mass of 1330 kg including occupants?

    asked on October 14, 2010
  8. grammar

    To no ones surprise, Joe didn't have his homework ready. A. no ones surprise B. noones surprise C. no-ones surprise D. no ones' surprise E. no one's surprise I put A but it was wrong and I don't know why?

    asked on October 20, 2010
  9. math

    mr. lee had a bag of red beans and a bag of black beans. 20% of the total number of beans were black, and there were 180 ounces more red beans than black beans. he transferred some red beans to the bag containing black beans, so that, the bag now contained

    asked on July 17, 2014
  10. math

    A hacker is trying to guess someone's password. The hacker knows (somehow) that the password is 14 characters long, and that each character is either a lowercase letter, (a, b, c, etc), an uppercase letter (A, B, C, etc) or a numerical digit (0, 1, 2, 3,

    asked on November 8, 2015
  11. math

    If 25 times were moved from Box A to Box B, there would be an equal number of dimes in both boxes. If 100 dimes were moved from Box B to Box A, the ratio of dimes in Box A to Box B would be 7:2. What was the original number of dimes in Box A?

    asked on July 21, 2014
  12. physics

    if two forces 10N and 20N are inclined at angle 60degree to each other. Find the resultant force.

    asked on September 27, 2015
  13. calculus

    If an arrow is shot upward on Mars with a speed of 52 m/s, its height in meters t seconds later is given by y = 52t − 1.86t2. (Round your answers to two decimal places.) What is the average speed over the given time intervals? (i) [1, 2] (ii) [1, 1.5]

    asked on January 31, 2018
  14. college physics

    Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car on the tracks. part a)If the train's mass is 3.8×10^5kg , how much force must he exert (find the magnitude)? part b)Compare to the weight of the train (give as %). partc)

    asked on April 29, 2012
  15. English

    1. I am into sports. (What is the meaning of this sentence?) 2. Exercise is good for the health. 2-1. Exercise is good for health. 2-2. Exercise is good for your health. 2-3. Exercise does good for people. (Are all correct?) 3. Our athletic meet took place

    asked on November 24, 2008
  16. physics vectors

    If vector A = (6.00 i -8.00 j) units, vector B = (-8.00 i + 3.00 j) units, and vector C = (25.0 i + 22.0 j) units, determine a and b such that (a vector A + b vector B + vector C= 0.) a=? b=?

    asked on August 24, 2016
  17. Statistics

    you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green die and 1 on

    asked on October 30, 2016
  18. Physics

    You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.5 m above the ground, and it is moving at a speed of 8.0 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the

    asked on September 6, 2014
  19. Chemistry

    In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm respectively. pHe = 1.50 atm. pNe = 2.00 atm. pAr = 8.40 atm - 1.50 - 2.00 = ?? mole

    asked on January 14, 2007

    A mixture of Xe, Kr, and Ar has a total pressure of 6.7 atm. What is the mole fraction of Kr if the partial pressures of XE and Ar are 1.6 atm and 2.8 atm? Did anyone get .343 ?

    asked on May 12, 2012
  21. Pre-Calc Helppp!!!

    Use the Law of Sines to solve for all possible triangles that satisfy the given conditions. (If an answer does not exist, enter DNE. Round your answers to one decimal place. Below, enter your answers so that B1 is smaller than B2.) a = 39, c = 40, angle A

    asked on March 31, 2012

    Consider a binomial random variable where the number of trials is 12 and the probability of success on each trial is 0.25. Find the mean and standard deviation of this random variable. I have a mean of 4 and a standard deviation of 2.25 is this correct

    asked on June 10, 2010
  23. math

    The lengths of the diameters of two concentric circles are 6 and 8. What is the distance between the circles?

    asked on July 24, 2014
  24. Statistics

    If my p-value = .322 and my significant level is .05 , then My Null Hypothesis is rejected and I must accept the Alternative hypothesis My Null Hypothesis is not rejected My Alternative hypothesis becomes the new Null Hypothesis I cannot make a decision

    asked on June 15, 2010
  25. English

    Parenthetical expressions include information that may be helpful but are not essential to the meaning of a sentence. They are de-emphasized by ________. A. dashes B. parentheses C. commas D. brackets I'm not really understanding this question. It has to

    asked on February 13, 2015
  26. Solar Energy

    With respect to a PV module's I-V and P-V curves, and the module's operating point, consider the following statements: a) When the operating point of the PV module is on the MPP (maximum power point), \(P_{mpp} \lt V_{oc} \times I_{sc} \) b) For a given

    asked on November 23, 2013
  27. MATH

    How many five-card hands chosen from a standard deck contain two hearts and three spades?

    asked on September 4, 2016
  28. math

    An investment of 25,000 earns interest at an annual rate of 8.4% compounded continuosly a. find the instantaneous rate of change of the amount in the account after years b. find the instantaneous rate of change of the amount in the account at the time the

    asked on January 22, 2017
  29. math

    Of the books in a library, 1/3 came from Robbie's collection and 15 came from Marta's. Of the rest, 15 were Elena's 1/5 were Winfield's, and 5 were purchased from the bookstore. How many book are there in the library?

    asked on July 30, 2014

    Can a frequency distribution have overlapping classes? i would say no ,but I believe i am wrong.

    asked on June 10, 2010
  31. Spanish

    What items do the Mapuche make that still have great value to the Spanish? There is more than one correct answer choice. Be sure to select all that apply. leather textiles ponchos pottery A and D?

    asked on February 11, 2020
  32. Physics

    A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.24 and the push imparts an initial speed of 3.8 m/s?

    asked on October 14, 2010
  33. Precalculus

    In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles ABC and DEF such that AB = DE, BC = EF, and angle A = angle D, then we cannot deduce that ABC and DEF are congruent. However, there are a few

    asked on February 24, 2014
  34. chemistry

    An aspirin tablet weighing 0.502 g has been analyzed and contains 68.2 % ASA (180.16 g/mol) by mass. A student dissolved the tablet in hot NaOH and the cooled solution was diluted with DI water to the mark in a 250 mL volumetric flask. Exactly 3.00 mL of

    asked on January 27, 2008
  35. Science

    Consider a lead-acid battery with 500 Ah capacity and a rated voltage of 12 V. a)What is the total capacity of energy in watt-hours that can be stored in the battery? b)Assume that the battery is completely empty. The battery is now charging at a C-rate of

    asked on June 5, 2017
  36. chemistry

    1. Calculate the standard enthalpy change for the reaction: C2H4(g) + H2(g) → C2H6(g) given that the enthalpy of combustion for the reactants and products are: ΔHºc(C2H4)(g) = -1411 kJ mol^-1 ΔHºc(C2H6)(g) = -1560 kJ mol^-1 ΔHºc(H2)(g) = -286 kJ

    asked on July 19, 2014
  37. math

    The cost of mailing a package is c cents for the first b ounces and d cents for each additional ounce. find the cost, in cents, for mailing a package weighing f ounces if f is more than b

    asked on July 24, 2014
  38. math

    A 3-m radius disk is rotating at 6 rad/sec. What is the linear speed of a point that lies on the circumference of the disk?

    asked on July 20, 2020
  39. World history

    Which temporary solution was adopted in 1924 to address the economic problems caused by Germany's inability to make reparations? A-Versailles plan B-Marshall plan C-Dawes plan D-young plan B?

    asked on July 13, 2018
  40. math

    Every cereal box has a gift inside, but you cannot tell from the outside what the gift is. The store manager assures you that 16 of the 58 boxes on the shelf have the secret decoder ring. The other 42 boxes on the shelf have a different gift inside. If you

    asked on November 8, 2015
  41. Math

    A quarter-circle with radius $5$ is drawn. A circle is drawn inside the sector, which is tangent to the sides of the sector, as shown. Find the radius of the inscribed circle. The rest is in asymptote size( 100 ) ; // Not to scale. Don't try anything here,

    asked on March 22, 2020
  42. Math

    Let f(x) be a polynomial such that f(cos theta) = cos(4 theta) for all theta. Find f(x). (This is essentially the same as finding cos(4 theta) in terms of cos theta; we structure the problem this way so that you can answer as a polynomial. Be sure to write

    asked on February 8, 2014
  43. math

    A group of 21 people went to the country fair with 9 people on a stagecoach and 3 people in each buggy. On the return trip, 4 people rode in each buggy. How many people returned on the stagecoach?

    asked on August 14, 2014
  44. math

    Carrie can inspect a case of watches in 5 hours. James can inspect the same case of watches in 3 hours. After working alone for 1 hour, Carries stops for lunch. After taking a 40 minute lunch break, Carrie and James work together to inspect the remaining

    asked on July 17, 2014
  45. Math

    Consider the matrix given. Explain why it is not orthonormal, then use the columns with Gram-Schmidt to create an orthonormal basis for its column space. -1

    asked on July 30, 2020
  46. math

    Jennifer went to the post office for stamps. She bought the same number of 8 cents stamps and 10 cents stamps. She also bought as many 2 cents stamps as both of the other two combined. How many of each kind did she get if she paid a total of $4.40 for them

    asked on December 25, 2017
  47. Physics

    A small disk of radius R1 is mounted coaxially with a larger disk of radius R2. The disks are securely fastened to each other and the combination is free to rotate on a fixed axle that is perpendicular to a horizontal frictionless table top. The rotational

    asked on December 2, 2011
  48. Chemistry

    Ni2+(aq)+Mg(s)→Ni(s)+Mg2+(aq) Indicate the half-reaction occurring at Anode. Indicate the half-reaction occurring at Cathode.

    asked on May 14, 2014
  49. Chemistry

    Calculate the pH of a solution at 25.0 °C that contains 1.94 × 10-10 M hydronium ions.

    asked on November 17, 2012
  50. English expression

    A. Listen carefully, and choose the picture suitable for the content of the dialogue. B. Listen carefully, and draw a line to find out who teaches which subject. Look at the two people on the left, and the textbooks on the right. Draw a line between while

    asked on March 8, 2008
  51. Finance

    Antiques ‘R’ Us is a mature manufacturing firm. The company just paid a dividend of $11.45, but management expects to reduce the payout by 4.5 percent per year, indefinitely. Required: If you require a return of 11 percent return on this stock, what

    asked on March 11, 2015
  52. Fraction

    A girl spends 1/4 of her pocket money on monday and 3/8 on wednesday. What fraction of her money is left

    asked on November 3, 2014
  53. Math

    Find the line of best fit for the points (1,-3), (-1, 4), (0,2), and (1,1).

    asked on July 30, 2020
  54. math

    Garrett throws a dart at a circular dart board. The dart board has a radius of 15 inches, and the bull’s eye in the center of the dart board has a radius of 2 inches. What is the probability that a dart thrown at random within the dartboard will hit the

    asked on May 2, 2019
  55. Calculus

    HELP PLEASE Find the minimum distance from the point (4, 2) to the parabola y^2=8x

    asked on March 17, 2010
  56. Analytic Geometry

    What is the equation of a circle passing through (-4,-4) and tangent to the line 2x-3y+9=0 at (-3,1)?

    asked on April 30, 2013
  57. Managerial Economics

    For a cost function C = 100 + 10Q + Q2, the average variable cost of producing 20 units of output is A. 10 B. 20 C. 30 D. None of the statements associated with this question are correct

    asked on February 5, 2009
  58. mathematics

    Explain the meaning of words,adverbial phrase, adverbial clause, adjectival phrase, adjectival clause.

    asked on July 15, 2020
  59. math

    A picture measures 12cm by 9cm is surrounded by s frame whose area is 100 square centimetres, find the width of the frame.

    asked on May 22, 2019
  60. math

    The difference between one half of a number and one fifth of it is 561. Find the number.

    asked on July 24, 2014
  61. Math

    Consider a right circular cylinder whose total surface area (top, bottom, side) is 300 pi; what must its radius be in order that the volume be as large as possible

    asked on June 15, 2013
  62. chemistry h/w help

    The concentration of lead nitrate (Pb(NO3 )2 ) in a 0.726 M solution is __________ molal. The density of the solution is 1.202 g/mL.

    asked on September 15, 2010
  63. Chemistry

    During which stroke of a four-stroke internal combustion engine is work done by the system of gases? A. Power stroke B. Intake stroke C. Compression stroke D. Exhaust stroke It isn't C because work is done to and not by

    asked on August 10, 2020
  64. Maths

    2 Similar Cups are 3cm&5cm deep,if larger Cup holds 625cm cube of water,find smaller cup Volume

    asked on December 7, 2018
  65. Physics

    Question: A Toyota car travelled at the rate of 70 km/hour leaves the house 2 hours after a Kia car has left and overtakes it in 5 hours. at what rate was Kia car travelling? What's the Formula pls? Thanks

    asked on July 21, 2016
  66. math

    The charge for renting a rowboat on Loon Lake is D dollars per hour plus c cents for each minute into the next hour. How many dollars will Mr.Wilson pay if he used a boat from 3:40 P.M. to 6:20 P.M.

    asked on July 27, 2014
  67. math

    In a certain class there are 12 boys and 18 girls. If the class average for an algebra exam is 90 and the boys' average score is 87, what is the girls' average score?

    asked on July 16, 2014
  68. Statistics

    Which of the following statements about the correlation coefficient r are true? I. It is not affected by changes in the measurement units of the variables. II. It is not affected by which variable is called x and which is called y. III. It is not affected

    asked on November 12, 2012
  69. physics

    Panic escape. The figure below shows a general situation in which a stream of people attempt to escape through an exit door that turns to be locked. The people move toward the door at speed vs = 3.7 m/s, are each d = 0.20 m in depth, and are separated by L

    asked on December 14, 2008
  70. chemistry

    a) whart chemical principle is the basis for the activity series of metals? b) What is the significance of the distance between two metals in the activity series?

    asked on March 27, 2008
  71. History

    Which explains how the Cold War affected politics in Nicaragua in the 1980s? A- The country was blockaded by NATO because of its alliance with the Soviet Union. B- The United States armed Nicaraguan Contras against the Socialist government in a civil war.

    asked on May 15, 2020
  72. statistics / probability

    A cooler full of sodas has 12 lemon-lime drinks and 18 gingerales. If one drink is selected at random and then a second drink is selected at random, what are the chances that both sodas will be gingerales?

    asked on January 5, 2018
  73. vectors linear algebra

    The parametric equations for a line L1 are as follows: x = −4−6t y = 2+2t z = 1−4t Let L2 be the line parallel to L1 and passing through the point (−3, −3, −3). Find the point P on L2 whose x-coordinate is −12. P=P(-12, _ , _ ) ?

    asked on October 26, 2015
  74. chemistry

    Calculate the standard cell potential for each of the electrochemical cells? 2Ag+(aq)+Pb(s)→2Ag(s)+Pb2+(aq) E∘cell......V? 2ClO2(g)+2I−(aq)→2ClO−2(aq)+I2(s) E∘cell......V? O2(g)+4H+(aq)+2Zn(s)→2H2O(l)+2Zn2+(aq) E∘cell......V?

    asked on April 11, 2014
  75. physics

    If a car rolls gently(vo=0) off a vertical cliff, how long does it take to reach 85km/h?

    asked on September 13, 2010
  76. Math

    If 30% of pupils in a school are boys,what percentage of the pupils are girls

    asked on February 26, 2019
  77. chemistry

    A student obtained an average PV value of 42,000 in column (f) of the data table. If the syringe had been able to be adjusted to a volume of 35.0 mL, what would the pressure be inside the flask?

    asked on November 5, 2014

    Two long straight aluminum wires, each of diameter 0.30mm, carry the same current but in opposite directions. They are suspended by 0.50m long strings...If the suspension strings make an angle of 3.0 degree with the vertical, what is the current in the

    asked on February 25, 2013
  79. physics 1

    In coming to a stop a car leaves skid marks 92m long on the highway. Assuming a decceleration of 7.00m/s^2, estimate the speed of the car just before braking.

    asked on September 13, 2010
  80. Physics

    An ice cube is placed in a microwave oven. Suppose the oven delivers 105 W of power to the ice cube and that it takes 32,200 J to melt it. How long does it take for the ice cube to melt?

    asked on March 16, 2010
  81. chemistry

    Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.

    asked on March 31, 2016
  82. chemistry

    4NH3(g)+5O2(g) yield 4NO(g)+6H2O(g) Deduce the equilibrium constant expression for the reaction.

    asked on April 26, 2012
  83. Chemistry

    Tarnish on iron is the compound FeO. A tarnished iron plate is placed in an aluminum pan of boiling water. When enough salt is added so that the solution conducts electricity, the tarnish disappears. Imagine that the two halves of this redox reaction were

    asked on May 14, 2014
  84. math

    A girl walks 3/4 of the way home in 18 minutes. At the same rate, she can walk the rest of the way home in A. 4 1/2 minutes B. 6 minutes C. 9 minutes D. 24 minutes

    asked on July 16, 2014
  85. Trigonometry - Slopes stuff

    Point A is the terminal point of angle phi and point B is the terminal point of angle theta. Point A is in the first quadrant and point B is in the second quadrant, while tan phi = 1 and tan theta = -7. Find the slope of AB. Ok so since A is in the first

    asked on October 18, 2013
  86. Physics

    A boat heads directly across a river with a velocity of 12 m/s. If the river flows at 6.0 m/s find the magnitude and direction (with respect to the shore) of the boat's resultant velocity.

    asked on November 5, 2011
  87. math

    One card is selected from a deck of cards. Find the probability of selecting a red card or a heart

    asked on November 25, 2010
  88. Statistics

    A clinic employs 9 physicians. 5 of the physicians are female. 4 patients arrive at once. Assuming the doctors are assigned randomly to patients, what is the probability that all of the assigned physicians are female?

    asked on March 25, 2009
  89. History

    Which most accurately describes how the Agricultural Revolution impacted the evolution of human society? The Agricultural Revolution led people to consume more protein and fewer grains. The Agricultural Revolution eliminated the need for animal husbandry

    asked on October 14, 2019
  90. physics vectors

    Consider the two vectors A with arrow = 3 i − j and B with arrow = − i − 6 j. Calculate the directions of A with arrow + B with arrow and A with arrow − B with arrow. A with arrow + B with arrow ° (counterclockwise from the +x axis) A with arrow

    asked on August 23, 2016
  91. Fraction

    A fruit grower uses 1/3 of his land for bananas,3/8 for pineapples1/6 for mangoes and the remainder for oranges. What fraction of his land is used for oranges?

    asked on November 3, 2014
  92. Fat gram calculator

    Design a program that asks the user for the number of fat grams and calories in a food item. Validate the input as follows. Make sure the number of fat grams and calories are not less than 0. According to nutritional formulas, the number of calories cannot

    asked on October 13, 2013
  93. science

    A chair of mass 15.5 is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 38.0 that is directed at an angle of 42.0 below the horizontal and the chair slides along the floor.Use Newton's laws to calculate

    asked on August 3, 2012
  94. Chem

    You place a test-tube of a room temperature reagent into a beaker of hot water. Which of the following statements are true? (Assume that there are no energy transfers between anything except the reagent and the water.) Choose at least one answer. a. q

    asked on November 2, 2010
  95. philosophy

    Q: Who claimed that our subjection to pain and pleasure should be the foundation for our laws? a. Simone de Beauvoir b. Kant c. Jeremy Bentham d. Peter Singer e. Aristippus I think it is C, but i am not sure about E... or possibly the other ones. Thank u!

    asked on November 26, 2006
  96. Algebra 2

    Subtract (2-4x^9+3x^3)-(7x+x^3-6+12x^4) and simplify

    asked on August 7, 2020
  97. Economics

    What is a potential negative outcome when the government seeks to ensure specific market outcomes? decrease in business tax incentives regulations that slow down innovations unpleasant information shared by businesses lack of consumer protection

    asked on June 18, 2020
  98. Chemistry

    A solution contains 0.0390 M Pb2 (aq) and 0.0390 M Sr2 (aq). If we add SO42–(aq), what will be the concentration of Pb2 (aq) when SrSO4(s) begins to precipitate? I am just completely lost on this one.

    asked on April 5, 2016
  99. math

    How long is a rectangular strip of land with a width of 5/4 km and an area of 3/4 square km ?

    asked on February 26, 2013
  100. calculus

    y = (ln x)^(cos4x) Use logarithmic differentiation to find the derivative of the function.

    asked on October 11, 2011