Scales and conversions - Middle grade

Adam was admiring the new boat that his father bought. The boat measures 20 feet in length. Adam wanted to draw the boat using a scale of ½ inch = 2 feet. What will the length of the boat in inches once Adam draws it on the paper?

Answer: 5 inches

Explanation:
To solve this problem we must set it up as a proportion as follows:

Notice that the units for feet cancel when we multiply the 2 feet by the 20 feet and we are lefts with only inches, which is what the problem requires.

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