math
posted by carlos on .
for the school play, child tickets cost $3 and adult tickets cost $5. The number of adult tickets sold was 20 more than the number of child tickets sold. If the total sales were $2540, how many adult tickets were sold?

Let X =$ child tickets
X+20 =$ adult tickets
5(X+20) + 3X=2540
Solving for X will give you the amount in dollars sold for children tickets. Plugging the value that you obtain for X into X + 20 will give you the amount of money earned for selling adult tickets. Divide that amount from X + 20 by 5 to get the number of adult tickets sold. 
65