JAMB 2018 · UTME · Q21✱✱

By selling 20 oranges for ₦1.35 a trader makes a profit of $8\%$ . What is his percentage gain or loss if he sells the same 20 oranges for ₦1.10?

Worked solution (try it first)

An $8\%$ profit means ₦1.35 is $108\%$ of the cost price.
So the cost price is $\frac{1.35}{1.08} = 1.25$ , that is ₦1.25.
Selling for ₦1.10 is less than ₦1.25, a loss of ₦0.15.
Percentage loss on the cost price: $\frac{0.15}{1.25} \times 100 = 12\%$ , option C.