Question

The length of a pencil is 7 inches and the width is 1/2 inches. Shawna created a scale factor of the pencil for art class. The model is 35 inches long. What is the width of the model?

Answer 1

Scaling

The real dimensions of a pencil are:

Length: 7 inches

Width: 1/2 inches

Shawna created a big pencil for the art class whose length is 35 inches.

Comparing the length of both pencils, we can find the scale factor:

$sc=\frac{model\text{ length}}{real\text{ length}}=\frac{35}{7}=5$

If the model is to be correctly scaled, then the width should be multiplied by the same scale factor, thus:

$ModelWidth=\frac{1}{2}\cdot5=\frac{5}{2}$

The width of the model pencil should be 5/2 inches or 2.5 inches.