Question

Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes, and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P,Q and R respectively. What is the proportion of the solution R in the liquid in the tank after 3 minutes?

Answer 1

Part filled by (A + B + C) in 3 minutes = 3 1/30 + 1/20 + 1/10 = 3 x 11/60 = 11/20
When c works for 1 min its work done in 1 min = 1/10

so when it works for 3 min its contribution = 3/10

Required ratio = 3/10 x 20 /11= 6 /11..
hope this will help you

Answer 2

Answer:

Part filled by (A + B + C) in 3 minutes = 3 1/30 + 1/20 + 1/10 = 3 x 11/60 = 11/20

When c works for 1 min its work done in 1 min = 1/10

so when it works for 3 min its contribution = 3/10

Required ratio = 3/10 x 20 /11= 6 /11..

hope this will help you