interest problem

Question

Peter deposited a sum of money in SouthEast Bank. The money grew to $1300 in 8 months. SouthEast Bank pays simple interest at the rate of 6% per year. How much did Peter deposit?

For this purpose only (not for your work or the exam), round to the nearest integer amount. Do not put the dollar sign.

Answer 1

the underlying formula that you want to use to solve here for simple interest is

A = P(1 + rt)

for this scenario that means taking

P = A / (1 + rt)

P = 1300 / (1 + 0.06*2/3)

P = 1300 / 1.04

P = 1250

meaning that the initial deposit here was $1250