Answer:
27 minutes by slower pump and 54 minutes by faster pump.
Explanation:
Let the faster pump can fill the tank in x minute.
The slower pump can fill the tank in 2x minutes.
Both fill the tank in 18 minutes.
In one minute faster pump will fill the tank,[tex]\frac{1}{x}[/tex]
In one minute slower pump will fill the tank,[tex]\frac{1}{2x}[/tex]
In one minute both pump will fill the tank,[tex]\frac{1}{18}[/tex]
According to question,
[tex]\frac{1}{x}+\frac{1}{2x}=\frac{1}{18}\\\frac{3x}{2x^{2} }=\frac{1}{18}\\\frac{2x^{2}}{3x}=18\\x=27[/tex]
Tank filled by faster pump will be, [tex]2x=2\times 27=54 minutes[/tex]
Therefore, the tank filled by slower pump in 27 minutes and by the faster pump in 54 minutes.
