Interest, Banking & Inflation is one of 9 topics in the Grade 12 Mathematical Literacy CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Simple interest is calculated:
Only on the original principal amount, for the entire period
On the principal plus all interest already earned in previous periods
Only in the final year of the investment or loan
Only on amounts over R10,000
Answer: Only on the original principal amount, for the entire period — Simple interest is calculated only on the original principal for the whole period, so the interest amount is the same every year.
Medium
2. R10,000 is invested at a simple interest rate of 8% per annum for 3 years. Using A = P(1 + rt), what is the total amount, in Rand, after 3 years?
Answer: 12400 — A = P(1 + rt) = 10,000 x (1 + 0.08 x 3) = 10,000 x (1 + 0.24) = 10,000 x 1.24 = R12,400.
Medium
3. Using the same investment as the previous question (R10,000 at 8% simple interest for 3 years, giving a total of R12,400), how much interest, in Rand, was earned in total?
Answer: 2400 — Interest earned = final amount - principal = R12,400 - R10,000 = R2,400.
