Maria invested $450 in a savings account and earned $126 in interest at the end of 7 years.

what was the interest rate?

a.
3.5%

b.
4%

c.
4.5%

d.
5%

The interest rate is B. 4%

Given:
Principal = 450
Interest = 126
term = 7 
rate = ?

Simple Interest is computed by multiplying the Principal, rate, and term.

Interest = P × r × t

126 = 450 × r × 7
126 = 3150r
r = 126/3150
r = 0.04 x 100% = 4%

To check:

I = 450 × 0.04 x 7
I = 18 × 7
I = 126