Question

Pipe A can fill a tank in 40 minutes, while Pipe B takes 60 minutes to fill the same tank.

If both pipes are used at the same time, how long will it take to fill the tank?

Answer 1

We can think of this problem in terms of the rate that each pipe fills the tank.
Since Pipe A takes 40 minutes to fill the tank completely, we can say that Pipe A fills 1/40 of the tank each minute
Similarly, Pipe B fills 1/60 of the tank each minute.
If both Pipes are working together, how much of the tank gets filled each minute? Well, what is 1/40 + 1/60?
And given that rate, how many minutes does it take for the tank to get completely filled?

Answer 2

It would be 80

Answer 3

Wouldn't you have to divide it in half or something?

Answer 4

1/24?

Answer 5

Yes! Ok, that's good, both Pipes together can fill 1/24 of the tank every minute.
So now, how many minutes would that take to fill the entire tank?

Answer 6

How would you figure out the amount of minutes it would take to fill the pipes, with the amount of information we have?

Answer 7

Sure, so we know that both pipes together fill 1/24 of the tank *every minute*; you figured that out yourself.
So, if 1/24 of the tank gets filled every minute...
After 1 minute, we have 1/24; after 2 minutes, we have 2/24...
Eventually, the entire tank 24/24 is filled. How long does that take?

Answer 8

It would take 24 minutes to get it filled. Because 1/24 after 1 minute is equal to 1/24 of the pipe filled. So then I after 24 minutes it would be filled completely or, filled 24/24.

Answer 9

Yes, perfect. Good work