An athletic director is ordering balls for two softball leagues. The 10 year old league uses an 11-inch softball priced at $2.75. The 12 year old league uses a 12-inch softball priced at $3.25. The bill smeared in the rain, but he remembered ordering 80 softballs for a total of $245. How many of each size did he order
If there are x 11" balls, there are 80-x 12" balls, so add up the costs:
2.75x + 3.25(80-x) = 245.00
x = 30