Question

Three pipes A, B and C can fill an empty tank in 15, 10 and 5 minutes respectively. When the tank is empty, the three pipes are opened simultaneously. What is the part of work done by B and C?
1. 9/11
2. 12/11
3. 6/11
4. 2/11

Answer 1

Correct Answer - Option 1 : 9/11

Given:

Time taken by A = 15 mins

Time taken by B = 10 mins

Time taken by C = 5 mins

Formula used:

Efficiency = Total work/Time taken

Calculation:

LCM of (15, 10 and 5) = 30 = Total work

Efficiency of pipe A = 30/15 = 2 units

Efficiency of Pipe B = 30/10 = 3 units

Efficiency of pipe C = 30/5 = 6 units

Total efficiency of A, B and C = (2 + 3 + 6) = 11 units

Part of work done by B and C in the tank = (6 + 3)/11 = 9/11

∴ The part of work done by B and C in the tank is 9/11