When will the two tanks have the same amount of water?

Question

The local zoo is filling two water tanks for the exotic fish exhibit. One water tank contains 50 gal of water and is filled at a constant rate of 10 gal/h. The second water tank contains 30 gal of water and is filled at a constant rate of 30 gal/h. When will the two tanks have the same amount of water?

Answer 1

The tanks will have the same amount of water in 1 hour.

To find this out, we can create two equations.

Let h = the number of hours, r = the amount of water in tank 1, and t = the amount of water in tank 2.

r = 50 + 10h

t = 30 + 30h

We want to find when r = t, so we will set our two equations equal to each other.

50 + 10h = 30 + 30h

20 = 20h

1 = h

When you solve for h, you find that h = 1.