If A can complete a work in 15 days and B can complete it in 25 days, how long will it take for A to finish the remaining work if they worked together for 5 days?
A and B can do a piece of work in 12 days and 15 days respectively. How long will they take to complete the work if A works alone for 4 days and then B joins him?
If a pipe can fill a tank in 6 hours and another pipe can empty it in 8 hours, how long will it take to fill the tank if both pipes are opened together?