Question

A and B are two taps which can fill a tank individually in 10 minutes and 20 minutes respectively. However, there is a leakage at the bottom which can empty a filled tank in 40 minutes. If the tank is empty initially, how much time will both the taps take to fill the tank (leakage is still there) ? ( A ) 5 ( B ) 10 ( C ) 7 ( D ) 8

Answer 1

Step-by-step explanation:

A's 1min work = 1/10

B's 1min work = 1/20

C's 1min work = 1/40

(A + B - C)'s = 1/10 + 1/20 + 1/40

= (4 + 2 + 1)/40

= 7/40

tank will filled in 40/7 = 5 + 5/7min