Solve
-One Pump Can Drain a Pool in 9 Minutes $3 \frac { 3 } { 5 } \mathrm {~min}$

Multiple Choice

Solve.
-One pump can drain a pool in 9 minutes. When a second pump is also used, the pool only takes 6 minutes to drain. How long would it take the second pump to drain the pool if it were the only pump in use?

A) $3 \frac { 3 } { 5 } \mathrm {~min}$
B) $\frac { 1 } { 18 } \mathrm {~min}$
C) $51 \mathrm {~min}$
D) $18 \mathrm {~min}$