Explain the different types of motion of a sewing machine​

How do i work this problem out using the equation a=pe^rt

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.

Find the amplitude of a sinusoidal function that models this temperature variation