Answer:
42 visitors
Step-by-step explanation:
Let x be the number of visitors that are older than 18 and y be the number of visitors that are 18 years or younger.
The art museum had a total of 224 visitors on Tuesday, then x+y=224.
Visitors older than 18 paid $12 for admission, so x visitors paid $12x. Visitors 18 years or younger paid $8 for admission, then y visitors paid $8y. The museum collected a total of $2,520, thus,
12x+8y=2,520.
From the first equation, x=224-y. Substitute it into the second equation:
12(224-y)+8y=2,520,
2,688-12y+8y=2,520,
4y=168,
y=42
and
x=224-42=182.
