The art museum had a total of 224 visitors on Tuesday. Visitors older than 18 paid $12 for admission. Visitors 18 years or younger paid $8 for admission. The museum collected a total of $2,520. How many visitors were 18 or younger?

Given:

total of 224 visitors

older than 18 paid $12

18 and below paid $8

total collection 2,520

Let l be visitors older than 18 and m be visitors 18 and below.

l + m = 224

12l + 8m = 2,520

l = 224 - m

12 (224 - m) + 8m = 2520

2688 - 12m + 8m = 2520

-4m = 2520 - 2688

-4m = - 168

m = - 168/-4

m = 42 number of visitors 18 and below.

l = 224 - m

l = 224 - 42

l = 182 number of visitors older than 18.

12 (182) + 8 (42) = 2520

2184 + 336 = 2520

2520 = 2520