Term 1 · Weeks 1–2 · Earning Money and Percentages

Challenge problem · non-routine

Challenge Non-routine

A vendor buys cabbages at ₱45 per kilo, marks them up 30%, then gives a 10% discount to regular customers. What is the vendor's profit per kilo on a discounted sale, as a percentage of cost?

Show step-by-step solution

Answer: 17 %

Marked-up price: $45 \times 1.30 = 58.50$ .
Discounted price: $58.50 \times 0.90 = 52.65$ .
Profit: $52.65 - 45 = 7.65$ ; as a percentage of cost $7.65/45 = 17\%$ .
Note that $+30\%$ then $-10\%$ is not $+20\%$ .

Common errors to watch for

Adding percentages: 30% − 10% = 20%.

Budget of Work competencies

gm11.t1.w1.c2
Apply a percentage increase or decrease in various contexts: