# JOHN

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

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

3. ## CHEMISTRY

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

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

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

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

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?

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?

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

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,

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?

12. ## physics

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

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]

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)

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

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=?

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

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

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

20. ## CHEMISTRY

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 ?

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

22. ## STATISTICS

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

23. ## math

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

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

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

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

27. ## MATH

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

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

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?

30. ## STATISTICS

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

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?

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?

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

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

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

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

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

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?

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?

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

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,

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

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?

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

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

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

53. ## Math

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

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

55. ## Calculus

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

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)?

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

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.

60. ## math

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

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

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.

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

64. ## Maths

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

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

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.

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?

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

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

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?

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.

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?

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, _ , _ ) ?

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?

75. ## physics

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

76. ## Math

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

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?

78. ## PLEASE COULD SOMEONE HELP ME OUT Physics

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

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.

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?

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.

82. ## chemistry

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

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

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

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

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.

87. ## math

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

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?

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

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

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?

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

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

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

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!

96. ## Algebra 2

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

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

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.