Associated Topics || Dr. Math Home || Search Dr. Math

### How Fast Did Dan Drive?

```
Date: 8/24/96 at 19:28:24
From: Anonymous
Subject: How fast did Dan drive?

I need an equation for this problem:

It takes Kay 20 minutes to drive to work at 45 mph. Two minutes after
she left home this morning, her husband Dan started out with her
briefcase, which she had forgotten. If Dan gets to the office just as
Kay does, how fast did he drive?

Thanks,  Dustin
```

```
Date: 8/25/96 at 15:15:32
From: Doctor Robert
Subject: Re: How fast did Dan drive?

Be careful not to mix minutes with miles per HOUR.  Kay drives at
45 mph for 1/3 of an hour, so she drives 45 x 1/3 = 15 miles.
Now Dan drives the same distance in 18 minutes (since he left two
minutes after she did).  Therefore, his speed must be distance
divided by time:

v = 15/(18/60hr) = 50 mph

-Doctor Robert,  The Math Forum
Check out our web site!  http://mathforum.org/dr.math/
```
Associated Topics:
Middle School Word Problems

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search