give solution

Question

pipe A can fill a tank in 50 minutes while pipe B takes an hour to fill it up.Pipe A is opened first and the tank starts filling up.After 17 minutes ,pipe B is also opened.In how many more minutes will the tank get filled up.

Answer 1

Hi, Teju.

Okay, so if pipe A fills up the tank in 50 minutes, then it fills it at a rate of t/50 where t is time in minutes.

Therefore, pipe B fills up in t/60

So, if pipe A filled by itself for 17 minutes, then it filled up 17/50 of the tank. So together, the two pipes only need to fill the last 33/50 of the tank.

So our equation is:

 

t/50 + t/60 = 33/50 

Now, multiply both sides by 300:

6t + 5t = 198

11t = 198

t = 18

So it will take 18 more minutes to fill up completely.