Question

Kate borrowed $400 from her friend. She will repay this amount plus 3 percent simple interest after one year. What is the total amount she will pay her friend?

Answer 1

The answer is $412.

Let's first calculate simple interest. Simple interest (I) can be expressed as:
I = P * r * t
P - principal
r - rate
t - time period

It is given:
I = ?
P = $400
r = 3% = 0.03
t = 1 year

Therefore:
I = P * r * t = 400 * 0.03 * 1 = 12

The total amount Kate will repay is the principal amount (P) plus 3% simple interest (I):
P + I = 400 + 12 = $412