Question

A tank can be filled by pipe A on 15 mins.

Answer 1

Answer:

can you post an good picture

Answer 2

Step-by-step explanation:

If all three pipes are in operation simultaneously, the time taken to fill the tank by pipes A,B and C => 1/(1/15+ 1/10+1/30) => 1/(2/30 +3/30+1/30)=>1/(6/30) => 5 minutes . It is given that after 3 minutes , pipe C is not used So in 5 minutes 100% of tank is filled then in 3 minutes 100(3/5)% => 60% of tank is filled. Hence 40% of tank needs to be filled by pipes A and B. time taken to fill the tank 100% by pipes A and B => 1/(1/15 +1/10) => 1/(10/150 +15/150) => 1/(25/150) => 6 minutes. So to fill only 40 % of tank we need 6(0.4) => 2.4 minutes to fill the remaining tank.

Hence in 2.4 minutes the remaining tank should be filled by pipes A and B. Hope it helps you.