Bunuel wrote:

MarFel wrote:

Hi,

Why do you assume that both tanks need the same amount of time? Should this be not stated in the question?

Because for example if the first tank needs 30 minutes because he has a much higher rate and the second one needs 60 minutes because of a lower rate, the time needed to reach the same level is 60 minutes.

BR

I think you misunderstood the question.

We have two tanks, X and Y, containing 500 and 200 gallons of water. Water is being pumped out of tank X at some rate and water is being added to tank Y at some rate. Now, obviously, after some time both tanks will have equal amount of water. The question asks to find that amount of time.

Hope it's clear.

Thx for your reply!

Still dont get it.

Your solutions says that:

500−kt=200+mt

My point is that t must not be equal on both sides because they can have different rates at which water is pumped out or in and need thus different amounts of time.

So my formula would be: 500-k*t1=200+m*t2

Which can not be solved for a valid solution.

To be more precise if water is pumped out of Tank X at a rate of 30 gallons per minute and water is pumped into Tank Y at 50 gallons per minute.

Tank X needs to loose 150 gallons and needs thus 150/30= 5 minutes and Tank Y needs to gain 150 gallons and thus 150/50=3 minutes. Thus the time is not equal.

Ahh okay got it now will leave it for others though.

The amount of water is not fixed we will just pump water out of tank X until it reaches the same level of tank Y. And that level is somewhere between 500 and 200.