Janice bought 30 items each priced at 30 cents, 2 dollars, or 3 dollars. If her total purchase price was $48.00, how many 30-cent items did she purchase?
Janice bought 30 items each priced at 30 cents, 2 dollars, or 3 dollars. If her total purchase price was $48.00, how many 30-cent items did she purchase?
The total purchase price is an even number of dollars
Therefore the number of 30¢ items has to be a multiple of 10
It can't be 30 because that would mean there are no items at $2 or $3
It can't be 20 because that would leave only 10 items at $2 or $3 and that isn't enough
Conclusion: There must be 10 items priced at 30¢
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