Answer
$$60$$
Work Step by Step
$$\eqalign{
& \int_0^6 {\int_1^2 {10} dy} dx \cr
& {\text{Integrate with respect to }}y \cr
& = \int_0^6 {\left[ {10y} \right]_1^2} dx \cr
& {\text{Evaluate the limits}} \cr
& = \int_0^6 {\left[ {10\left( 2 \right) - 10\left( 1 \right)} \right]} dx \cr
& = \int_0^6 {\left( {20 - 10} \right)} dx \cr
& = \int_0^6 {10} dx \cr
& {\text{Integrate}} \cr
& = \left[ {10x} \right]_0^6 \cr
& {\text{Evaluate}} \cr
& = 10\left( {6 - 0} \right) \cr
& = 60 \cr} $$
