Re: bag of marbles question 5th grade HELP!

In article <42244$47fad5af$45283fd7$2586@[EMAIL PROTECTED]
>, Marvel
<goh@[EMAIL PROTECTED]
> wrote:

> What would the formula be?
> 
> In a bag of  red and black marbles there are 18 fewer red marbles than
black
> 
> If 45% of the marbles are red how many marbles are in the bag. 
> 
> 

The problem is about red and black marbles and asks a question about
"how many" so it seems a good start would be to let R be the number of
red marbles and B the number of black marbles.

Now translate:

"there are 18 fewer red marbles than black" i.e. R = B - 18.

"45% of the marbles are red" A little trickier; 45% of _all_ the
marbles are red i.e. R = 0.45(R + B).

So,

R = B - 18 and
R = 0.45(R + B).

Can you take it from there? If not, get back to us.

-- 
Paul Sperry
Columbia, SC (USA)