# On Carrie's map, Greenville and North Valley are 4.5 inches apart, on her map is 1 inch 20 miles. How far is Greenville from North Valley?

Jul 29, 2017

See a solution process below:

#### Explanation:

We can write this as:

$1$ inch is to $20$ miles as $4.5$ inches is to what?

Or

$1 \text{ in" -> 20" mi":4.5" in} \to x$

Or

(1" in")/(20" mi") = (4.5" in")/(x

To solve this last equation we can first do a cross product or cross multiply the equation:

$1 \text{ in" * x = 20" mi" * 4.5 "in}$

$1 \text{ in"x = 90" in" * "mi}$

$\left(1 \text{ in"x)/(1" in") = (90" in" * "mi")/(1" in}\right)$

$\left(\textcolor{red}{\cancel{\textcolor{b l a c k}{1 \text{ in")))x)/color(red)(cancel(color(black)(1" in"))) = (90color(red)(cancel(color(black)(" in"))) * "mi")/(1color(red)(cancel(color(black)(" in}}}}\right)$

$x = \frac{90 \text{ mi}}{1}$

$x = 90 \text{ mi}$

Greenville is $\textcolor{red}{90}$ mile from North Valley.