Math (hard)
posted by Courtney on .
Postcard stamps are 20 cents each, while letter stamps are 33 cents each. If you have 50 stamps worth $12.60, how many of each type do you have?
I don't even know where to begin with this Q.

let the number of 20 cent stamps be x
then the number of 33 cent stamps is 50x
solve:
20x + 33(50x) = 1260 
After solving the equation i get 3.9=x
??? isnt there a way you can solve it by letting x= number of postcard stamps and then y= number of letter stamps? 
sure:
number of postcards stamps x
number of letter stamps y
x + y = 50
20x + 33y = 1260
from the first:: y = 50x
then in the second
20x + 33(50x) = 1260
well, look at that! I had that in the first line.
solution:
20x + 1650  33x = 1260
13x = 390
x = 30
then y = 50x = 5030 = 20
(how did you get a decimal??? of 3.9x ? ) 
THANK YOU!!!!!! sorry! i feel like a waste of time for you, but im just not that smart ;)