There were 5 times as many adults as children at a funfair. After 14 of the adults left the funfair and 55 more children arrived, the number of adults and the number of children became the same. How many people were there at the funfair at first?
Need a hint?
Let the children at first be 4 units, so that 14 of the adults is a whole number of units.
Worked answer
- Let the children at first be 4 units. Then the adults are 5 × 4 = 20 units.
- Adults who left = 14 of 20 units = 5 units, so 15 units of adults stayed.
- Children after = 4 units + 55.
- 15 units = 4 units + 55, so 11 units = 55.
- 1 unit = 55 ÷ 11 = 5.
- People at first = 20 units + 4 units = 24 units = 24 × 5 = 120.
Answer: 120 people
The mistake this question tests
Habit
Stopped at one part in ratio
Some pupils give only the number of adults at first (20 units = 100) and forget to add the 20 children.
How to fix it at home →Wrong answers children often give:
- 100 Calculation slip
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See the answer →Practise PSLE whole numbers until the mistakes stop.
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