the volume of a rectangular prism is just the product of its height, length and width.
let's firstly convert the mixed fraction to improper fraction and then multiply.
[tex]\bf \stackrel{mixed}{1\frac{1}{4}}\implies \cfrac{1\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{5}{4}} ~\hfill V=\cfrac{5}{4}\cdot 4\cdot 2\implies V=10 \\\\\\ ~\hspace{34em}[/tex]
