If you ride down a straight 3-mile section of highway that has an 8% grade, how far do you drop vertically?

If you can help, Thank you! :]

OK, what that means is for every 100 feet you drop 8'. 8%= 8/100.

Any help now?

2nd hint. Proportions and unit conversions
3rd hint: Not the only way to do the problem.

I misled you a bit, but not by much.

8% is 0.08 or it is 8/100

Depending on how your supposed to do the problem depends on the answer. Let's look at this:

\frac{8}{100}*3 mi * \frac{5280}{1}\frac{ft}{mile}

If you want the answer in miles, get rid of the 5280' feet/mile conversion. If you keep, the 5280, your answer will be in feet.

If you need fractional answers, then it's perfectly acceptable to have an answer in fractional miles.

It's very typical in the construction trades to convert say a 2% slope to so many inches per 10 feet. For example a 2% slope means it drops 2.4 inches every 10 foot. Rulers don't normally measure in tenths and 2% doesn't have to be exact when doing this.

So, I'm reading more into the problem that I should have.

When you look at the solution, the units cancel. This cancelling of units will become very important when doing other sorts of problems.

8/100 * 3 miles will give an answer in miles.

You may have to show this as (8*3)/100 or (2*4*3)/(4*25)
or 6/25 of a mile and not 0.24 miles.

Note, I factored the 8 and I factored the 100 and 4/4 equals 1, so the numerator 4 and denominator 4 cancel.

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Oh sorry.. I'll remember that..
And thanks so much!!