Question

Mikayla opens a savings account with a principal balance of $3,000. After 5 years, she earns $450 in interest. Using the equation I=prt, where I=interest, p= principal, r=rate, and t=time.

What is the interest rate on Mikayla's account after 5 years?

Answer 1

3% is the interest rate. Using the formula I=PRT, you can simply derive the rate by putting the given numbers in.

I = 450
P = 3,000
R = ?
T = 5 Years

The equation now goes,
450 = 3,000 * R * 5
450 = 15,000 * R
450/15,000 = R
0.03 = R

 multiply it by 100,

R = 3%