Question 185494
 For a school band trip, Marcia decides to order T-shirts for all of the participants. It will cost $4 per shirt for the medium size, and $5 per shirt for the large size. Marcia orders a total of 70 T-shirts and spends $320. How many are medium shirts?
(the answer is: 30 medium T-shirts, but i dont know how to solve it?) 
----------------------------
Ooooooh, you gave away the ending, now it won't be any fun.
m = # of mediums
g = # of large (l looks too much like a one)
m + g = 70 total # of shirts
4m + 5g = 320 (total cost)
Can you finish it?  If not, email me via the thank you note.