Chapter 20, Problem 37TAS

To determine

The mass percentage of the oxides $\text{Mgo}$, $\text{FeO}$ and ${\text{SiO}}_{\text{2}}$ in pyroxene, ${\text{MgFeSiO}}_{\text{6}}$ and (a) The amount of silica in $225\text{kg}$ of pyroxene, (b) The mass percentage of silica in remaining liquid if $325\text{kg}$ of olivine and $225\text{kg}$ of pyroxene have crystallized out of $1000\text{kg}$ of magma.