6 pipes can fill a tank in 1 hour 24 minutes. How long will it take to fill the tank if 7 pipes of the same type are used?

6 pipes are required to fill a tank in 1 hour 20 minutes. How long will it take if only 5 pipes of the same type are used?

6 pipes are required to fill a tank in 1 hour 20 minutes. How long will it take if only 5 pipes of the same type are used?

6 pipes are required to fill a tank in 1 hour 20 minutes.How long will it take if only 5 pipes of the same type are used?

12 pipes, all of the same size, fill a tank in 42 minutes. How long will it take to fill the same tank,if 21 pipes of the same size are used ?

6 pipes can fill a tank in 24 minutes. One pipe can fill in

Two pipes A and B can fill a tank in 12 and 15 minutes respectively. A third pipe C can empty it in 10 minutes. How long will it take to fill in the tank if all pipes are opened simultaneously ?

A tank can be filled by 5 pipes in 80 minutes. How long it will take to fill the tank by 8 pipes of same size?