If the principal P = $600, the interest I = $210, and time t = 5 years, find the following.

Question

(a) What is the rate

Answer 1

P = Po + I = 600.
Po + 210 = 600
Po = 600 - 210 = $390.

I = Po*r*t = $210.
390*r*5 = 210
1950r = 210
r = 0.1077 = 10.8 %.