Question P5–P6 The equal concept
The total cost of 2 identical files and 1 pen is $19.05. The total cost of 3 such files and 5 such pens is $44.50. Find the cost of 1 pen.
Answer
1 pen costs $4.55.
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The question tells you a part of one pile equals a part of another.
In this one. Multiply each purchase until the item you do not want appears the same number of times in both — then the difference between the two totals is made of the wanted item alone.
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Children compare the two fractions without first relating them to a common whole. A smaller fraction of a larger group can be bigger than a larger fraction of a smaller group.
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