SOLUTION: I need help with this question... If n pencils cost S cents, how much would k pencils cost, in cents? Thank you!

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Question 410154: I need help with this question...
If n pencils cost S cents, how much would k pencils cost, in cents?
Thank you!

Found 2 solutions by scott8148, Edwin McCravy:
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
cost of one pencil ___ S/n

cost of k pencils ___ k * (S/n) ___ kS/n

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!

First look at four examples using numbers.  That way we can figure
out how to do the problems, and then we'll do the same thing using
the letters that stand for numbers:

If 3 pencils cost 12 cents, then 1 pencil would cost 4 cents,
because I divided 12 by 3 and got 4, so 8 pencils cost 32 cents,
because I multiplied 4 by 8 and got 32 cents.

If 4 pencils cost 20 cents, then 1 pencil would cost 5 cents,
because I divided 20 by 4 and got 5, so 19 pencils cost 95 cents,
because I multiplied 5 by 19 and got 95 cents.

If 6 pencils cost 12 cents, then 1 pencil would cost 2 cents,
because I divided 12 by 6 and got 2, so 11 pencils cost 22 cents,
because I multiplied 2 by 11 and got 22 cents.


If 12 pencils cost 60 cents, then 1 pencil would cost 5 cents,
because I divided 60 by 12 and got 5, so 13 pencils cost 65 cents,
because I multiplied 5 by 13 and got 65 cents.

Therefore:

If n pencils cost S cents, then 1 pencil would cost S%2Fn cents, 
because I divided S by n and got S%2Fn, so k pencils cost expr%28S%2Fn%29k cents,
because I multiplied S%2Fn by k and got expr%28S%2Fn%29k cents.

Edwin