The ratio of boys to girls in a class is 3 : 5. There are 12 more girls than boys. How many pupils are there in the class?
Worked answer
- Girls − boys = 5 units − 3 units = 2 units = 12.
- 1 unit = 6.
- Class = 8 units = 8 × 6 = 48 pupils.
Answer: 48 pupils
The mistake this question tests
Habit
Stopped at one part in ratio
You found part of the class. The whole class is 8 units.
How to fix it at home →Wrong answers children often give:
- 6 Stopped at one part in ratio
- 18 Stopped at one part in ratio
- 30 Stopped at one part in ratio
- 96 Calculation slip
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See the answer →Practise PSLE ratio until the mistakes stop.
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