Answer:
Adults = 1,200
Children = 600
Explanation:
Children = $2
Adults = $4
Total people in the zoo = 1800
Total Revenue = $6,000
Let
y = number of children in the zoo
x = number of adults in the zoo
x + y = 1,800 (1)
4x + 2y = 6,000 (2)
x = 1800 - y
Substitute x = 1800 - y into (2)
4(1800 - y) + 2y = 6000
7200 - 4y + 2y = 6000
Collect like terms
4y - 2y = 7200 - 6000
2y = 1200
Divide both sides by 2
y = 1200/2
y = 600 children
Substitute y = 600 into (1)
x + y = 1,800
x + 600 = 1,800
x = 1,800 - 600
= 1,200
x = 1,200 adults