Pipes A and B together can fill an empty tank in 30 hours, whereas pipes B and C together can fill it in 24 hours. A, B and C together can fill the tank in 20 hours. In how many hours can pipe B alone fill 35% of the tank?

Ten men or twelve women can finish the same work in 10 days. If 5 men and 2 women undertake the work together, how many days will they take to complete the work?

A can do 40% of a work in 12 days, whereas B can do 60% of the same work in 15 days. Both work together for 10 days. C completes the remaining work alone in 4 days. A, B and C together will complete 28% of the same work in :

Pipes A and B can empty a full tank in 36 and 45 minutes, respectively, whereas pipe C alone can fill the tank in 15 minutes. B and C are opened together for 15 minutes, and then both are turned off and A is opened. Pipe A will empty the tank in (in minutes):