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mathgrl_3905
Nov 24, 2006, 09:01 AM
I could use a little help with figuring out this word problem.
Could anyone help me?

James bought 80 postage stamps for which he paid $18.40. Some were 1 cent stamps and some were 33 cent stamps. How many of each kind did he buy?

charlie123
Nov 24, 2006, 09:06 AM
OK - this what I figured out. I'm not sure if there is more than one answer...

55 .33 stamps
25 .01 stamps


55x.33=18.15
25x.01=.25

18.15+.25=$18.40

HOpe this helps!

mathgrl_3905
Nov 24, 2006, 09:16 AM
How would you get that? You just guessed until you got it right?

galactus
Nov 24, 2006, 09:39 AM
I agree with Charlie.

Let x=number of one-cent stamps
Let y=number of 33-cent stamps

x+y=80... [1]
0.01x+0.33y=18.40... [2]

Solve [1] for y: y=80-x

Sub into [2]: 0.01x+0.33(80-x)=18.4

26.4-0.32x=18.4

0.32x=8

x=25

Therefore, there are 25 one-cent stamps and 55 33-cent stamps.