# Math Help - Scale speed question

1. ## Scale speed question

A model car 1:32 scale goes 200 feet in 16 seconds. What is the scale speed of the car.

I've got to the point of:

200 feet *32 = 6400 feet

6400/5280 = 1.21212121 mile

16 secs to go 1.212121 mile = ? mph

Am I setting this up right?

2. Perfectly.

3. Originally Posted by HBF
16 secs to go 1.212121 mile = ? mph

Hi HBF,

Here's how you can figure mph. Note that there are 3600 seconds in an hour.

$1.212121212...=\frac{40}{33}$

$\frac{\frac{40}{33}\ \ mi}{16 \ \ sec}=\frac{x \ \ mi}{3600 \ \ sec}$

Solve for x. That's a fast car!