the scale on aroad map indicates that 1/4 inch equals 20 miles. How far apart in miles are two towns that are 3 1/2 inches away on the map.

How many fourths are in 3 1/2? Ans:14

So the distance must be 14*20

3.5" x (20 miles/0.25") = ??

Check my work.

The answer in my book is 280. I can not figure out how to write the equation using proportiions using cross multiply. I have tried several ways and unable to get the answer in the book.

0.25 / 20 = 3.5 / x

Cross multiply:

0.25x = 70
x = 280

Thank you !

To determine the distance between two towns that are 3 1/2 inches away on the map, we can use the given scale of 1/4 inch equals 20 miles. Here's how you can calculate it step by step:

1. Start by converting the fractional distance on the map to a decimal. In this case, 3 1/2 inches can be written as 3.5 inches.

2. Use the scale to convert the inches on the map to miles. Since the scale is 1/4 inch equals 20 miles, we can set up a proportion:

1/4 inch = 20 miles
3.5 inches = x miles

Cross-multiplying, we get:
(1/4) * x = (3.5) * 20

Simplifying:
x/4 = 70

Multiply both sides by 4 to solve for x:
x = 4 * 70
x = 280

3. The distance between the two towns is 280 miles.

So, the two towns are 280 miles apart.