Question

If 4/5 of a cistern is filled in 1 minute, how much more time will be required to fill the rest of it?​

Answer 1

Answer:

Solution: Time taken to fill 4/5 of cistern = 1 min. By unitary method: Time taken to fill the one empty cistern = 1 x 5/4 =5/4 min = 1 min 15 sec.