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By integrating the constant 1 with respect to $z$ from 0 to 2, the inner integral evaluates to 2. This leaves a double integral $\int_{0}^{3}\int_{0}^{4} 2 \, dy \, dx$, which represents the volume under the constant surface $z(x,y)=2$ over the $xy$-region.

Conditions: The region is a rectangular box with constant top surface $z=2$.; The integral is evaluated in the order $dz \, dy \, dx$.

By integrating the constant 1 with respect to $z$ from 0 to 2, the inner integral evaluates to 2. This leaves a double integral $\int_{0}^{3}\int_{0}^{4} 2 \, dy \, dx$, which represents the volume under the constant surface $z(x,y)=2$ over the $xy$-region.

Conditions: The region is a rectangular box with constant top surface $z=2$.; The integral is evaluated in the order $dz \, dy \, dx$.