Answer
$140mL$ is required to get $10.5mL$ of Gantrisin.
Work Step by Step
We are given that the ratio of Gantrisin is $1.5g/20mL$
To find $mL$ required to get $10.5 g$ of Gantrisin, let the mL required be $'x'$.
Therefore,
$\frac{1.5}{20}=\frac{10.5}{x}$
$x=\frac{10.5*20}{1.5}$
$x=\frac{10.5*20}{1.5}$
$x=140mL$
