Ravi had 16 small identical baskets and 15 large identical baskets. He used 660 oranges to fill 9 small baskets and 6 large baskets completely. The number of oranges needed to fill 4 large baskets completely was the same as the number needed to fill 5 small baskets completely.
- How many oranges were needed to fill a small basket completely? [3]
- How many more oranges did Ravi need to fill the remaining baskets completely? [2]
Need a hint?
Since 4 large baskets hold the same as 5 small baskets, let one small basket be 4 units and one large basket be 5 units. Then count how many units the 9 small and 6 large baskets make.
Worked answer
- (a) 4 large baskets = 5 small baskets, so 1 small basket = 4 units and 1 large basket = 5 units.
- 9 small baskets = 9 × 4 = 36 units. 6 large baskets = 6 × 5 = 30 units.
- 36 units + 30 units = 66 units, and 66 units = 660 oranges, so 1 unit = 660 ÷ 66 = 10 oranges.
- 1 small basket = 4 × 10 = 40 oranges. 1 large basket = 5 × 10 = 50 oranges.
- (b) Small baskets left = 16 − 9 = 7. Large baskets left = 15 − 6 = 9.
- Oranges needed = 7 × 40 + 9 × 50 = 280 + 450 = 730 oranges.
The mistake this question tests
Stopped at one part in ratio
Many pupils divide 660 by 15 baskets to get 44 for every basket. The small and large baskets hold different numbers of oranges, so they cannot share one amount.
How to fix it at home →More PSLE whole numbers questions
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See the answer →Practise PSLE whole numbers until the mistakes stop.
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