Question

There are 5,280 feet in a mile. If Sarah ran 13,200 feet, then how many miles did she run?

Answer 1

1 1/2
miles

5 1/2
miles



3 1/2
miles


2 1/2
miles

Answer 2

You are given the conversion factor as:

5280 ft = 1 mile

Write the conversion factor as a fraction. There are two possibilities shown below.

\(\dfrac{5280~ft}{1~mile} = \dfrac{1~mile}{5280~ft} = 1\)

Now start with the given number:

\(13,200~ft\)

You want miles, not feet.

If you multiply a quantity in ft by a fraction that is miles over ft, the ft will cancel out, and you are left with miles. That means you need to multiply 13,200 ft by \(\dfrac{1~mile}{5280~ft} \). Also, since both conversion fractions equal 1, multiplying by them will not change the amount, just the units.

\(13,200 ~ft \times \dfrac{1~mile}{5280~ft} \)

Do the multiplication. What do you get?