Question (21/28)
Two pipes A and B can separately fill a cistern in 60 minutes and 75 minutes respectively. There is third pipe C in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 minutes. In how much time the third pipe alone can empty the cistern ?(A) 90 minutes
(B) 100 minutes
(C) 110 minutes
(D) 120 minutes
Question (22/28)
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 opened. What is proportion of solution out of pipe C in the tank after 3 minutes ?(A) 5/11
(B) 6/11
(C) 7/11
(D) 8/11