Answer
$V = 1.5$
The volume of rain collected in the rain gauge is 1.5 cubic inches
Work Step by Step
$R = i-2j$
$A = 0.5~i+j$
We can find V:
$V = \vert ~R \cdot A ~\vert$
$V = \vert ~( i-2j) \cdot (0.5~i+j) ~\vert$
$V = \vert ~(1)(0.5)+ (-2)(1) ~\vert$
$V = \vert ~-1.5 ~\vert$
$V = 1.5$
The volume of rain collected in the rain gauge is 1.5 cubic inches
