CAT Exam Numerical Ability Time and Work

Two pipes can fill a tank in 15hr and 12hr respectively while a third pipe can empty it in 20hrs.if the tank is empty and all the three pipes are opened the tank will be full in

Read Solution (Total 2)

10 hours

In 1 hour
fraction filled by 1st pipe = 1/15
Fraction filled by 2nd pipe = 1/12
Fraction emptied by 3rd pipe = 1/20
Together in 1 hr
Fraction filled = 1/15 + 1/12 - 1/20
=1/10

===> tank will be filled in 10 hours
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1/15 + 1/12 -1/20(since it is emptying) = 1/10
so, it takes 10hrs to fill the tank.
10 years agoHelpfull: Yes(0) No(0)

CAT Other Question

If x and y are even integers, then the no of solutions of x^2-y^2=7389746232 Two pipes a and b fill a tank in 15 hrs and 20 hrs respectively. while a third pipe c can empty the full tank in 25hrs. all the three pipes are opened in the beginning. after 10hrs,c is closed. in how much time, will the tank be full?