Problem Solving

Four small pumps and two large pumps are filling a tank. Each of the small pumps works at three-fifths the rate of the large pump. If all \(6\) pumps work at the same time, they should fill the tank in what fraction of the time that it would have taken if only one large pump and only one small pump were working together?

A. \(1/7\)
B. \(2/9\)
C. \(3/8\)
D. \(4/11\)
E. \(5/12\)

OA D