Question P6 Working backwards
Today’s problem — free all day, every step. Every day has one.
A jacket was sold at a 20% profit for $168. What was the cost price?
See all 6 steps
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You know how it ended. Undo each step, last one first.
In this one. The profit is a percentage of the cost price, so the selling price is 120% of the cost — $168 is the 120%, not the 100%.
Also uses: Units and parts
The question gives the final amount after a sequence of changes and asks what the amount was 'at first' or 'to begin with'.
Children undo the steps in the same order they happened rather than in reverse, or forget that a percentage profit is added to the cost price, so the final price is 120% of it, not 100%.
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