Question P4–P5–P6 Suppose and swap
Today’s problem — free all day, every step. Every day has one.
A bakery packs 15 baskets of bread for a market stall. Each small basket holds 3 loaves and each large basket holds 5 loaves. Altogether the baskets hold 51 loaves. How many large baskets are there?
Answer
There are 3 large baskets and 12 small baskets. Check: 3 + 12 = 15 baskets, and 3 × 5 + 12 × 3 = 15 + 36 = 51 loaves, so both conditions are satisfied.
Suppose everything is one kind, then swap one at a time until the total is right.
In this one. Assume every basket is the smaller type, find the shortfall, then divide by the fixed increase from changing one small basket into one large basket.
Two kinds of thing are mixed together with a known total count and a known total of something else, such as legs or sweets, and neither kind's count is given on its own.
Children lose track of whether a swap adds to the total or takes away from it. Compare the starting total with the target first, then swap in the direction that closes the gap.
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