WAEC 2020 · Paper 1 · Q7

An amount of ₦550,000.00 was realised when a principal $x$ was saved at $2\%$ simple interest for 5 years. Find the value of $x$ .

Worked solution (try it first)

Simple interest for 5 years at $2\%$ is $5 \times 2\% = 10\%$ of the principal $x$ .
The amount is principal plus interest, so $1.1x = 550\,000$ .
Divide both sides by 1.1: $x = 500\,000$ .
The principal is ₦500,000.00, option D.