Posted by **carolyn** on Monday, September 15, 2008 at 11:27am.

Rachel loves to color. One of her fat crayons wears down to nothing after 15 hours and her skinny crayon wears down to nothing after 6 hours.. One day she starts coloring at 10:30am with two crayons one fat one skinny with the same height. At what time will the skinny crayon be 1/2 height of fat crayon

- crayon riddle 8th grade -
**bobpursley**, Monday, September 15, 2008 at 11:39am
The amount of crayon left is the original length-amount used.

The amount used depends on time. Now if one assumes both were the same original length (not stated in problem), then

lengthskinny=orglength-time*origlength/6

lengthfat=origlength-time*origlength/15

so if lenghtskinny=1/2 lengthfat, then

1/2lengthfat=Lo(1-time/6) and

lengthfat=Lo(1-time/15)

I would divide the first equation by the second...

1/2= (1-time/6)/(1-time/15)

multiply both sides by 2(1-time/15)

and it ought to solve quickly.

Nice problem: compliments to the originator.

## Answer this Question

## Related Questions

- linear equations - Rachel has two crayons. The fat crayon burns down to nothing ...
- linear equations - Rachel has two crayons. The fat crayon burns down to nothing ...
- Math - A jar contains 1 blue crayon, 1 green crayon, 1 black crayon, and 1 red ...
- math - Suppose that a crayon weighs the same as a marker. You have a box of ...
- Math ms sue please help!!!!!! - Simple probability You have 20 crayons to choose...
- Probability - CHECK ANSWERS - I have an eight pack of crayons. Colors red, green...
- math - a store donates 2 3/4 cases of crayons to a daycare center. each case ...
- 6th grade math - Rachel completed 3/4 of her cleaning in 4 hours. How many total...
- Physics - A skier wears a jacket filled with goose down that is 15mm thick. ...
- Probability - A man has 10 ties to choose from. He wears a tie each day to work...

More Related Questions