I need help for the last one

Richard save $32 in march he saved $48 in april and $38 in may then richard spent $113 on a keyboard how much money does richard have left

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.

The expression 1.01*1.005(^t) gives the amount of money, in thousands of dollars, in carter's savings account (t) years after he opens it. what does 1.01 represent in this expression?