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
An inequality to find this would be
308 = 22b, or b = 308/22
Either way, your answer would be b = 14.