Hi! Short math question

Ineed in figuring out this problem.

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Find the volume of the solid whose base is the region bounded by f(x), g(x) and the x-axis on the interval [0, 1], and whose cross-sections perpendicular to the y-axis are squares. your work must show the integral, but you may use your calculator to evaluate it. give 3 decimal places for your answe