Can someone help I need the answer fast

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

The cross-sectional areas of a right triangular prism and a right cylinder are congruent. the right triangular prism has a height of 6 units, and the right cylinder has a height of 6 units. which conclusion can be made from the given information? the volume of the triangular prism is half the volume of the cylinder. the volume of the triangular prism is twice the volume of the cylinder. the volume of the triangular prism is equal to the volume of the cylinder. the volume of the triangular prism is not equal to the volume of the cylinder.

The graph shows the distance kerri drives on a trip. what is kerri's speed?