CAT Exam Numerical Ability Time and Work

A pipe can fill a tank in 15 min and the other can empty it in 30 min. if both the pipes are opened at the same time and after 15 min if the second pipe is closed, then upto what level will the tank be filled?

Read Solution (Total 4)

Sorry its 1/15 - 1/30 [not 1/20]
15/450 = 1/30

In 15 mins = 15 * 1/30 = 1/2

Filled part = 1/2
Remaining part yet to be filled = 1/2
10 years agoHelpfull: Yes(12) No(0)

Half filled

Both pipes opened together,
fraction filled in 1 min = 1/15 - 1/30
=1/30

Since both pipes are opened for 15 min,
Fraction filled = 15*1/30 = 1/2

After 15 min tank will be half filled
10 years agoHelpfull: Yes(3) No(0)
a's 1 hr work = 1/15
b's 1 hr work = 1/20

in 1 min the tank filled ll be
1/15 - 1/20 = 5/300 = 1/60

in 15 mins, 15 * 1/60 = 1/4

in 15 mins, 1/4 part of the tank ll be filled...
Reaming tank yet to be filled = 3/4

Filled part = 1/4
Remaining part = 3/4
10 years agoHelpfull: Yes(1) No(0)
15(1/15 - 1/30)=1/2
out of total 1/2 will be filled.
10 years agoHelpfull: Yes(0) No(0)

CAT Other Question

A cistern normally fills in 8hrs, but due to leakage in its base it takes two more hours for the cistern to be filled in,if the cistern is full how long will it take to be emptied through the leakage? 4/5 part of a tank fills in a minute, then how much time will it take for the rest of the tank to be filled?