00:01
And the question says one pump fills a tank two times as fast as another pump.
00:05
If the pumps work together, they fill the tank in 18 minutes.
00:08
How long does it take for each pump to fill the tank? so the slow pump can fill one, and we don't know how fast it can fill it.
00:18
We know that the fast pump can fill one two times as fast as the first one.
00:24
And then we know together they can fill the tank in each.
00:30
18 minutes.
00:32
So we need to find a common denominator here, which is going to be 2x.
00:38
So i'm going to multiply the slow pump by 2.
00:43
So now this is 2 over 2x plus 1 over 2x equals 1 over 18.
00:53
So now we have 2 plus 1 over 2x equals 1 over 18, which is 3 over 2 .5.
01:04
So now we have 2 plus 1 over 2x 2x plus 1 over 18.
01:07
Now i'm going to use cross multiplication.
01:11
So 2x times 1 is 2x, and then 18 times 3 is 64...