If the first and second letters in the word PREPAYMENT were interchanged, the third and the fourth letter, the fifth and sixth letters and so on, which letter would then be eighth letter counting to your left?
Two pipes A and B can fill a tank in 16 hrs and 12 hrs respectively. The capacity of the tank is 240 liters. Both the pipes are opened simultaneously and closed after 2 hrs. How much more water need to fill the tank?