Answer
$48.0 \space mL$ for both cylinders.
Work Step by Step
1. Find the volume of the cubes:
$$V_{cube} = side^3 = (2.0 \space cm)^3 = 8.0 \space cm^3$$
Since: $1 \space mL = 1 \space cm^3 \longrightarrow V_{cube} = 8.0 \space mL$
2. When we simply add a cube to a graduated cylinder with some water, the final volume is equal to the sum of the volumes.
$$V_{final} = V_{water} + V_{cube} = 40.0 \space mL + 8.0 \space mL$$ $$V_{final} = 48.0 \space mL$$
Since both cubes and cylinders have the same volume, the result is equal for both.
