# 300 mile race

• Sep 22nd 2010, 07:55 PM
yoman360
300 mile race
300 mi race. If you are 20 mi closer to the finish than the start are many miles have you traveled?

The answer in the back of the book is: 160 mi. WHY?

I tried figuring out and i cant
• Sep 22nd 2010, 08:00 PM
Wilmer
S............a...............[you].......a-20.........F
a + a-20 = 300
• Sep 22nd 2010, 08:01 PM
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Quote:

Originally Posted by yoman360
300 mi race. If you are 20 mi closer to the finish than the start are many miles have you traveled?

The answer in the back of the book is: 160 mi. WHY?

I tried figuring out and i cant

Didn't understand what you meant at first, I see you mean you are 20 mi closer to the finish line than you are to the start line.

call your distance to start line x

then your distance to finish line is 300-x

we have 300-x = x-20

that is, your (distance to finish line) equals (distance to start line) minus 20.

solve for x.
• Sep 22nd 2010, 08:07 PM
yoman360
thanks I got 170 when i attempted it. I did this half 300=150 then 150 +20= 170 mi
• Sep 22nd 2010, 08:11 PM
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Quote:

Originally Posted by yoman360
thanks I got 170 when i attempted it. I did this half 300=150 then 150 +20= 170 mi

when you solve you get 2x=320 (or using Wilmer's letter 2a=320) and you calculate 320/2=160. You're doing things out of order.