A water tank has the shape of a rectangular prism of base 50 cm2. This tank is being filled at the rate of 12 liters per minutes. Find the rate at which the height of the water in the water tank increases; express your answer in millimeters per second.
February 3, 2014
Two different schools (A and B) have the same number of pupils. The ratio of the boys in school A and the boys in school B is 2:1 and the ratio of the girls in school A and the girls in school B is 4:5. Find the ratio of the boys in school A to the girls in school A.
February 2, 2014
Grade 5 Maths
A coin box contained some twenty-cent and fifty-cent coins in the ratio 4:3. After 20 twenty-cent coins were taken out to exchange for fifty-cents coins of the same value and put back in the box, the ratio of the number of twenty-cent coins to the number of fifty-cents coins ...
January 19, 2014
Ken and Sam shared some marbles. The ratio of the number of marbles Ken has to the number of marbles Sam has is 5:3. If Ken's marbles increases by 15%, what percentage of Sam's marbles must be decreased so that the total number of marbles they have remained unchanged?
January 1, 2014
Mrs Koh bought some pens, files and erasers. The ratio of the number of pens to the number of files to the number of erasers she bought was 1 : 2 : 3. The cost of each pen and eraser is $2.50 and $0.50 respectively. If she spent $60 on the pens and the erasers, how many files ...
December 30, 2013
The ratio of the number of males to the females at a performance is 5 : 7. 1/4 of the males and 3/4 of the females are children. What is the ratio of the number of adults to children? Express your answer in simplest form.
December 30, 2013
Donna wants to cut out circular discs of radius 7cm from a cardboard measuring 50cm by 70cm. What is the maximum number of circular discs that can be cut out from the cardboard?
December 29, 2013
This bank machine has four rows of buttons 1 2 3 4 5 6 7 8 9 0 Sam has a 4-digit bank number that uses one button from each row. For example his bank number could be 0571. How many different possibilities for Sam's bank number are there? The answer should be 648
December 1, 2013
The storekeeper found that if he removed the apples from his box either 2,3,4,5 or 6 at a time there was always one left over. However, if he removed the apples 7 at a time there was no apples left. If the box holds 500 apples, how many apples does the storekeeper have?
November 27, 2013
24 1c coins are set out in a row on a table Then every 2nd coin is replaced by a 2c coin every 3rd coin is replaced by a 5c coin every 4th coin is replaced by a 10c coin every 5th coin is replaced by a 20c coin every 6th coin is replaced by a 50c coin and every 7th coin is ...
November 19, 2013
A pie is cut into two equal parts. The first part of the pie is shared between Abdul and Kate. Kate has 3 times as much as Abdul. The second part of the pie is shared between Sarah and Ron. Ron has 3/5 as much as Sarah. The mass of Sarah's share of the pie is 200 grams. ...
November 7, 2013
Alan is using matchsticks to make isosceles triangles. Isosceles triangles have at least two sides the same length.How many different single isosceles triangles can he make with 45 matchsticks, using all the matchsticks each time? The answer is 11, but I can only work out 7, ...
November 6, 2013
lf you added a fifth of one and a quarter to one and a quarter, what would the answer be ? ..... The answers is 1 1/2 have tries 0.2 + 0.25 + 0.75 = 1.20 or 1 1/5 ???? 0.2 + 0.75 + 1 + 0.25 = 2.20 ??? Please help!
November 1, 2013
1. Lee Holmes deposited $16,700 in a new savings account at 6% interest compounded semiannually. At the beginning of year 4, Lee deposits an additional $41,700 at 6% interest compounded semiannually. At the end of year 6, what is the balance in Lees account? 2.Bill Moore...
October 29, 2013
This question has mentioned 'pattern of numbers', does that means not just do simple calculation from left to right OR there is a fast way to solve this question, please help. Look at this pattern of numbers. 7x 11 x 13 x 1 = 1001 7x 11 x 13 x 2 = 2002 7x 11 x 13 x 3...
October 21, 2013
If 10 DNA template molecules are used and 20 cycles of PCR, how many copies of a template would be amplified? I am pretty sure I cannot use 2^n (n equals the number of amplification cycles)because I don't have a single molecule of starting DNA template. How do I do this?
April 2, 2013
A light beam containing red and violet wavelengths is incident on a slab of quartz at an angle of incidence of 50.0°. The index of refraction of quartz is 1.455 at 660 nm (red light), and its index of refraction is 1.468 at 410 nm (violet light). Find the dispersion of the...
April 1, 2013
The amount of energy released by burning a fuel source, measured in energy per mass, is called the fuel value. If all the energy obtained from burning 1.25 pounds of butane (fuel value is 10.85 kcal/g) is used to heat 120.0 kg of water at an initial temperature of 21.2 °C...
March 22, 2013
a farmer wishes to fence off a rectangular field with 1,000 feet of fencing.if the long side of the field is along a stream, express the area of the field as a function of its width
October 13, 2012
Chem- Percent Yield
When HgO is heated, it decomposes into elemental mercury and diatomic oxygen gas. If 42.9 g of Hg is obtained from 70.1 g of the mercuric oxide, what is the percent yield of the reaction?
October 11, 2012
Determine the concentration of a solution of Mg(NO3)2 given the precipitate formed is 2.97 g and there are 50mL of Mg(NO3)2 and 50 mL of NaOH. Please show all work for each step clearly
September 18, 2012
The amount of iron in a meteorite was determined by a redox titration using KMnO4 as the titrant. A 0.4408 g sample was dissolved in acid and the liberated Fe3+ quantitatively reduced to Fe2+. Titrating with 0.0220 M KMnO4 requires 41.38 ml to reach the end point. Unbalance ...
April 11, 2012
0.1802 g sample of a chlorocarbon compound was analyzed by burning in oxygen and collecting the evolved gases in a solution of sodium hydroxide. After neutralizing, the sample was treated with 39.50 mL of a 0.025 M AgNO3. This precipitated the Cl- as AgCl and left an excess of...
April 11, 2012
An experimental alloy contained by copper and tantalum. 3.7950 g of the alloy was dissolved and analyzed gravimetrically. The copper was precipitated and weighed as CuO, a mass of 0.1805 g was obtained. Calculate the %w/w Cu in the alloy. [Answer in 2 decimal places]
April 11, 2012
please any one help me for this questionnnnnnnn ý need urgently At the end of the spring term, a high school physics class celebrates by shooting a bundle of exam papers into the town landfill with a homemade catapult. They aim for a point that is 31.1 m away and at ...
February 27, 2012
please any on help me for this question ý need urgently. The position of a particle moving along the x-axis is given by x = 3.49t2 2.21t3, where x is in meters and t is in seconds. What is the position of the particle when it achieves its maximum speed in the ...
February 27, 2012
please any one help me for this question The figure shows the paths of a golf ball your friend drops from the window of her apartment and of the rock you throw from the ground at the same instant. The rock and the ball collide at x = 34.14 m, y = 17.75 m, and t = 2.71 s. If ...
February 27, 2012
Which compound is more polar: water or dicloromethane? I know that water is a polar molecule but I dont know the polarity of dicloromethane or how to figure out which one is more polar than the other?
February 20, 2012
1)When Regardless of what the ministry of love did to you what one thing according to Winston could they never do in the book 1984? 2)describe the event that promoted winston's mother disappearance 3)how does julia give winston hope about the future when they are sure to ...
December 14, 2011
I need some help to explain this sentence: "Suddenly summoned to witness something great and horrendous, we keep fighting not to reduce it to our own smallness." from John Updike
September 13, 2011
A cannon placed at the top of a 100.0 m high cliff fires horizontally to a platoon of Hussars situated initially 1.0 km away from the base of the cliff. At what initial velocity should the cannon shell be fired assuming the hussars are moving with a constant speed of 10 m/s ...
July 10, 2011
A cart of 2kg travellin @6m/s collides wit another cart of mass of 0.4kg travellin in the same direction @ 2m/s. The 2kg cart bounc off and cöntinues wt 3m/s in the same direction after impact.calculate the velocity of the 0.4kg trolley afta collision
June 7, 2011
If 31.00 mL of a dilute solution of lime water (calcium hydroxide) required 10.10 mL of 0.246 M hydrochloric acid solution for neutralization to a methyl red end point, calculate the molarity of the lime water. Can you please explain how to do it? Do I use M1V1=M2V2?
April 2, 2011
investigators at an agricultural research facility randomly assigned equal numbers of chicken to be housed in two rooms. In room #1, chickens experienced normal day/night cycles. In the other room, lights were left on 24 hours a day. The objective was to see which group of ...
March 24, 2011
Political Science: American Government
Can you please tell me if these are correct? Thank you! Generally, people with lower incomes, less education, and lower job status: a. are more conservative in their political opinions. b. are more liberal in their political opinions. c. are more moderate in their political ...
March 11, 2011
The net operating cash flow generated year 1 is $ 85,500. computed as follows: Incremental income $ 110,000 Less Depreciation 40,000 ( 20% of 200,000) Net Income after depreciation $ 70,000 Income Tax 35% $ 24,500 ( 35% of 70,000) Net Income after Tax 45,500 Add : depreciation...
February 23, 2011
Bill wants to write the equation that demonstrates the model for explaining quarter-life crisis. He is using optimism, locus of control, income, and years since completing college as explanatory variables. Which of the following equations is most appropriate? Answer = a + b1X1...
February 17, 2011
Which of the following is true of the association between brand loyalty and attitude toward the brand? As brand loyalty increases, attitude toward the brand increases There is a moderately strong relationship between the two variables . The relationship can be attributed to ...
February 17, 2011
you have received a business research study done by a consultant for a life insurance company. The study is a survey of customer satisfaction based on a sample of 600. You are asked to comment on its quality. What do you look for?
February 7, 2011
an electron and a proton are initially very far apart (effectively an infinite distance apart.) they are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.29 x 10 -11 m. what is EPE final - EPE initial, which is ...
May 2, 2010
three charges are fixed to an x, y coordinate system. a charge of +18 µC is on the y axis at y= +3.0 degree m. a charge of -12 µC is at the origin. last, a charge of +45 µC is on the x axis at x= +3.0 m. determine the magnitude and direction of the net ...
April 27, 2010
consider three identical metal spheres a b and c. sphere a carries a charge of +5q. sphere b carries a charge of -q. sphere c carries no net charge. spheres a and b are touched together and then separated. sphere c is touched to sphere a and separated from it. last, sphere c ...
April 22, 2010
If water is lost at 20ft^3/day when W= 10,000 ft^3 then the leakage rate constant in the differential equation is 20/10,000 or 0.002. Suppose that water flows in at F= 200,000 ft^3/day. How much water would you predict in the lake after 100 days?\ W = Ce^(-kt)
February 7, 2010
Is (5,2) a solution of 4x-2y=-6 I said no, am I right? I am working on another problem where they want to know if this system of equations is perpendicular or parallel or neither,5x+4y=2, 4x-5y=4 I said neither. Is this right? I am to solve by using elimination: 2x+3y=1, 4x+6y...
January 8, 2010
Confused one said all were right, but the other said the first coordinates had a problem with the sign, only one is negative , so would't the answer be negative,or is it in-fact right? I re-did it and came up with the same answer... what is wrong with that one?
January 8, 2010
Is (5,2) a solution of 4x-2y=-6 I said no, am I right? I am working on another problem where they want to know if this system of equations is perpendicular or parallel or neither, I said neither. Is this right? I am to solve by using elimination: 2x+3y=1, 4x+6y=2 I keep ...
January 8, 2010
Hello there i am writing a book and i would like to know how many subjects does an eleventh grader have per day. please reply as soon as possible. thank you very much. P.S: This question is meant to be answered by an american individual due to various reasons.
November 6, 2009
2.Depends on what results you're talking about. A higher percentage gel will cause the DNA samples to migrate more slowly but it won't normally change the relative order of the bands in a given lane. Higher percentages can give better separation of small fragments, but...
December 21, 2008