You may have added 80 to the 150, because the height is 8 more and the base sum is 10 more. Be sure to use the joint variation equation $\displaystyle{y}={k}{x}{z}\usepackage{cmbright}\Huge\$ to find the constant of variation, k. Then use that value of k along with the second set of values for x and z in a second joint variation equation to solve for y. The correct answer is 350 square centimeters.