Question

Two taps A and B can fill a tank in 10 hours and 12 hours respectively. If the two taps are opened at 10 a.m., then at what time (in p.m.) should the tap A be closed to completely fill the tank at exactly 4 p.m.?​

Answer 1

Answer:

5 hours

Step-by-step explanation:

A's one hour work = 1 /10

B's one hour work =1 /12

(A +B)'s one hour work = 1/12 + 1/10 = 11/60

Let A is tuned after x hours

A's x hours + B's 6 hours work = 1

1/10* x + 1/12*6 = 1

x/10 + 1/2 = 1

x+5/10 = 1

x + 5 = 10

x = 10 - 5

x = 5