Tamara invests $30,000 in an account earning 7% interest per year over the next 4 years.

Question

How much (simple) interest will her investment earn in total?

Answer 1

the first thing you do is divide 30000 with 100:
300 = 1%
multiply it by seven to count the percentage
300x7 = 2100
multiply it by 4 to count the total via years
2100x4 = $8400

The answer is $8400 in total :)

Answer 2

I = PRT
(Interest, I = Principal, P * Rate, R * Time, T
P = 30,000
R = 7% = 0.07
T = 4

I = 30,000 * 0.07 * 4
I = 2100 * 4
I = 8400