P and Q completed a work together and were paid ₹1,080 and ₹1,440, respectively. If P can do the entire work in 20 days, how many days did they take to complete the work together?

If 'A' is 7 times as efficient as 'B', 'B' takes 32 days to complete the task, then find the number of days required to finish the whole work by 'A' and 'B'  working together.

To complete a certain task. X is 40 % more efficient than Y, and Z is 40% less efficient than Y. Working together, they can complete the task in 21 days. Y and Z together worked for 35 days. The remaining work will completed by X alone in:

Pipes A and B can fill a tank in 10 hours and 40 hours, respectively. C is an outlet pipe attached to the tank. If all the three pipes are opened simultaneously, it takes 80 minutes more time than what pipes A and B together take to fill the tank. A and B are kept opened for 7 hours and then closed and C was opened. C will now empty the tank in :