There are 3 taps, A, B and C, in a tank. These can fill the tank in 10 h, 20 h and 25 h, respectively. At first, all three taps are opened simultaneously. After 2 h, tap C is closed and tap A and B keep running. After 4 h, tap B is also closed. The remaining tank is filled by tap A alone. Find the percentage of work done by tap A itself.

A. 75%

B. 52%

C. 72%

D. 32%

Answer: Option C

Solution (By Examveda Team)

C's work done in 2 hour = 4 × 2 = 8
B's work done in 4 hour = 5 × 4 = 20
A's share of work = 100 - 28 = 72