Two taps A and B can fill a tank in 8 minutes.?

Question

If A alone can fill it in 24 minutes, in how many minutes does tap B fill it?

Answer 1

~What is the rate of flow for the two taps? Or, at the very least, what is the output of tap B relative to that of tap A?

Answer 2

A & B do it in 8. A alone in 24. If B were exactly as fast as A, it would take 12 minutes for both together, but together they do it faster, in 8 minutes, so B must be faster than A. B must do it alone faster than 24 minutes, but slower than 8 minutes. 24 upper bound; 8 lower bound

Consider what happens in just one minute:
In one minute, A does 1/24 of the tub. In one minute A&B together do 1/8 of the tub. In one minute B does 1/x of the tub. X is the unknown, the answer to the original question.


Write an equation for what happens in one minute, where 1/8 of the tank is filled:
1/x + 1/24 = 1/8 Solve the equation for x. Multiply the equation by 24. 24/x + 1 = 24/8 = 3 Solve the equation for x. 24/x + 1 = 3 24/x = 2 x=12

That looks like the right range of answer. because we knew at first that x must be between 8 and 24.

B is twice as fast as A. B is doing twice as much of the work. A does one third of the work, and B does 2/3 of the work.

This all assumes the two taps work independently of each other. That turning on tap B doesn't change the flow of tap A. Each tap alone might go faster if only one tap is on. If they interfere with each other, you might want a B tap to do it faster alone than just 12 minutes.

Or if you're doing the same problem with people, working together might be more efficient, so that their the total output is greater than just measuring the individual output of each and adding them together. If the taps open up a flow that feeds on each other, you could have a B tap that was slower alone than just 12 minutes.

The correct answer is somewhere between 8 and 24, 12 is correct, if there's no dependence between taps, somewhere between 8 and 12 if there's interference between taps, and somewhere between 12 and 24 if there's a joint increase in efficiency by working together.

Why is it teachers don't like these answers? and they never have these answers on multiple choice questions with scan answer sheets.

Of course, it really depends on what brand of tap you have, the height above sea level, atmospheric conditions, how cold it is, the freezing point of your fluid, whether you had a union plumber, whether you paid your water bill, and whether your tank is leaking. Whether the tank is a bathtub and how many people are in the bathtub, and who else needs to use the bathroom.

Answer 3

A can fill the tap in 24 minutes ,
that means in 1 minute A can fill 1/24th of the tank

say B can fill the tank in x minutes
that means in 1 minute B can fill 1/x of the tank

similarly,
A and B can fill the tank in 8 minutes,
that means in 1 minute A and B can fill 1/8 of the tank

so,

1/24 +1/x =1/8

solving,
1/x= 1/8 - 1/24

we get,
x=2/24 =12

B can fill the tank alone in 12 minutes

Answer 4

Assume x is the rate of A and y is the rate of B, then V=(x+y)*8 and V=x*24 and V=y*t, where V is the volume to be filled, t to be found; thus x=V/24 and y=V/t, hence V=(V/24+V/t)*8 or 1/8=1/24+1/t or 1/t=1/8-1/24 or 1/t=1/12 and t=12 minutes

Answer 5

enable faucet A take x minutes to fill the tank on my own So in a million minute it is going to fill a million / x of the tank in addition enable faucet B take y minutes to fill the tank on my own So in a million minute it fills a million/ y of the tank faucet A + faucet B take 80 minutes to fill the tank mutually So mutually in a million minute they fill a million /80 of the tank a million /x + a million/ y = a million/80 10/ x + 12 /y = 2/15 MULTIPLY EQUATION a million by ability of 10 10 / x + 10/ y = a million/8 (A) 10/x + 12/y = 2/15 (B) (B) - (A) 2/y = 2/15 -a million/8 = a million/one hundred twenty y = 240 minutes a million /x + a million/240 = a million/80 a million/x = a million/80 - a million/240 = 2/240= a million/one hundred twenty x = one hundred twenty minutes answer faucet A = 2 hours faucet B = 4 hours verify faucet A = a million/one hundred twenty X10 = a million/12 faucet B = a million/240 X12 = a million/20 a million/12 +a million/20 = 8/60 = 2/15

Answer 6

T/(A + B) = 8 MIN
T/A = 24 MIN
A = T/24 MIN
A + B = T/8 MIN
B = T/8 - T/24
B = T(3/24 - 1/24)
T/B = 24/2 = 12 MIN

Answer 7

Rather than give you the answer, I'll give you a hint for how to do it. The formula for solving a problem like this, where two people can do something within different times is this:

(x*y)/(x+y)=total time

where x=time for person A to do something, and y= time for person B to do something. That should be all you need.

Answer 8

12 min

Answer 9

we cant' do your homework for you!