2012 Pascal Problem 23

Mike has two containers. One container is a rectangular prism with width 2 cm, length 4 cm, and height 10 cm. The other is a right cylinder with radius 1 cm and height 10 cm. Both containers sit on a flat surface. Water has been poured into the two containers so that the height of the water in both containers is the same. If the combined volume of the water in the two containers is 80 cm^3, then the height of the water in each container is closest to

\textbf{(A)}\ 6.8 \text{ cm}\quad \textbf{(B)}\ 7.2 \text{ cm}\quad \textbf{(C)}\ 7.8 \text{ cm}\quad \textbf{(D)}\ 8.2 \text{ cm}\quad \textbf{(E)}\ 8.6 \text{ cm}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Pascal contests here.