Knowbotic
RatioStructured · 4 marks

Hao, Priya and Siti sold some raffle tickets at a school carnival. Each ticket cost $3.50. Hao sold 13 of the tickets. Priya and Siti sold the rest of the tickets in the ratio 7 : 2. Priya sold 40 more tickets than Hao.

  1. How many tickets did the three of them sell altogether?
  2. How much more money did Priya collect than Siti?
Need a hint?

Give the whole amount 27 units so that Hao's 13 is a whole number of units. Find the units for Priya and Siti from the remainder.

Worked answer

  1. (a) Hao sold 13, so the rest is 23. The rest is shared in the ratio 7 : 2, which is 9 parts. Make the whole 27 units, so each third is 9 units and Hao sold 9 units.
  2. The rest is 23 of the total = 2 × 9 = 18 units.
  3. Priya and Siti share 18 units in the ratio 7 : 2. Since 7 + 2 = 9 parts, each part = 18 ÷ 9 = 2 units. Priya = 7 × 2 = 14 units, Siti = 2 × 2 = 4 units.
  4. Priya − Hao = 14 − 9 = 5 units, and this is 40 tickets. 1 unit = 40 ÷ 5 = 8 tickets.
  5. Total = 27 units = 27 × 8 = 216 tickets.
  6. (b) Priya − Siti = 14 − 4 = 10 units = 10 × 8 = 80 tickets.
  7. Money = 80 × $3.50 = $280.
Answer: $280

The mistake this question tests

Habit

Fraction of a remainder

Many pupils split the whole in the ratio 7 : 2 instead of only the rest after Hao's share, or they forget to multiply the ticket difference by the price in part (b).

How to fix it at home →

More PSLE ratio questions

All ratio structured questions (problem sums) →

Practise PSLE ratio until the mistakes stop.

Three PSLE questions, free, no sign-up. You’ll see exactly where the marks went. Then 7 days of everything for S$4.99.