JAMB Mathematics 2011 Paper

Concept:Simple interest is earned on the original principal, and the time must be expressed in years before applying the formula.Explanation:The simple interest formula is $S.I. = \frac{P \times R \times T}{100}$.Principal $P = N5,000$, rate $R = 4\%$, and time $T = 9$ months.Convert $9$ months into years: $T = \frac{9}{12}$ years.Substitute into the formula: $S.I. = \frac{5000 \times 4 \times 9}{100 \times 12}$.Simplify step by step: $5000 \times 4 \times 9 = 180,000$.Then divide: $S.I. = \frac{180,000}{1200} = 150$.Therefore, the simple interest is N150.Answer:A. N150