Decide What Values of the Variable Cannot Possibly Be Solutions $\frac { 1 } { 19 } \mathrm {~min}$

Decide what values of the variable cannot possibly be solutions for the equation.
-A water tank can be filled in 9 minutes and emptied in 10 minutes. If the drain is accidentally left open when the tank is being filled, how long does it take to fill the tank?

A) $\frac { 1 } { 19 } \mathrm {~min}$

B) $\frac { 1 } { 90 } \mathrm {~min}$

C) $\frac { 90 } { 19 } \mathrm {~min}$

D) $90 \mathrm {~min}$