"Paul Sperry" <plsperry@[EMAIL PROTECTED]
> wrote in message
news:080420082317189931%plsperry@[EMAIL PROTECTED]
> In article <148b5$47fc23bb$45283fd7$18621@[EMAIL PROTECTED]
>, Marvel
> <goh@[EMAIL PROTECTED]
> wrote:
>
>> "Paul Sperry" <plsperry@[EMAIL PROTECTED]
> wrote in message
>> news:080420080115029670%plsperry@[EMAIL PROTECTED]
>> > 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)
>> >
>> I'm getting back because I don't get R = 0.45(R + B).
>
> R + B is all the marbles 45% of which are red.
>
>> Now I see 45% and 55% who have a difference of 10 and 18 is the 10.
>>
>> So eighteen is ten per cent of the entire thing, meaning one hundred
>> eighty
>> is 100%
>
> A more elementary i.e. better way than mine. In fact, you went straight
> for the answer where I found R and B and added them. If T is the total
> number of marbles, R = 0.45T and so B = 0.55T so 0.1T = B - R = 18.
>
>> Marvel
>> Charlotte N.C. USA
>
> A virtual neighbor.
>
> --
> Paul Sperry
> Columbia, SC (USA)
We go used to go to Chieko's over off Alpine Road until she sold out.
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