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?
Pipe A can fill a tank in 16 minutes and pipe B can empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes?