At what rate will the interest on N400 increases to N24 in 3 years reckoning in simple interest?

A.
3% 
B.
2% 
C.
5% 
D.
4%
Correct Answer: Option B
Explanation
Using simple interest = (frac{P times T times R}{100}),
where: P denoted principal = N400
T denotes time = 3 years
R denotes interest rate = ?
24 = (frac{400 times 3 times R}{100})
24 x 100 = 400 x 3 x R
R = (frac{24 times 100}{400 times3})
= 2%