Question

Three small pumps and one large pump are filling a tank. Each of the three small pumps works at 2/3rd the
rate of the large pump. If all 4 pumps work at the same time, then they should fill the tank in what fraction
of time that it would have taken the large pump alone?
(1) 4/7 (2) 1/3 (3) 2/3 (4) ¾

Answer 1

According to me the answer should be 4/7.. as u can easily evaluate the pumping rate by adding Thier rates and dividing them by 4...