"Two pipes A and B can separately fill a cistern in 60 minutes and 75 minutes respectively
Channel: Doubtnut
Date: 2020-04-05

"Two pipes A and B can separately fill a cistern in
 60 minutes and 75 minutes respectively. There is a third pipe 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? 
`90\ m in`
b. `100\ m in`
c. `110\ m in`
d. `120\ m in`"