The lunchroom is full of students: 40% are girls and the remainder are boys. There are 2 monitors for every 15 students. There are 8 monitors. Every boy drinks, on average, 1 carton of milk, and every girl drinks, on average, 2 cartons of milk. How many total cartons of milk are consumed by the students in the lunchroom?
Thoughts? Step-by-step reasoning:
There is 1 monitor for every fifteen students because 30 / 2 = 15. There are 120 students because 8 x 15 = 120. 60% of the lunchroom is boys because 100 - 40 = 60. There are 72 boys because 120 x .6 = 72. There are 48 girls because 120 x .4 = 48. The boys drink 72 cartons of milk because 72 x 1 = 72. The girls drink 96 cartons of milk because 48 x 2 = 96. They drink 168 cartons of milk because 72 + 96 = 168.
Thus, the answer is 168.