Answer:
150 adults and 270 children
Explanation:
Let there are x adults and y children.
ATQ,
x+y=420
or
y=420-x ....(1)
Adult visitors pay $3 and children visitors pay $1. on one day, the zoo collected a total of $720.
ATQ,
3x+y=720...(2)
Put equation (1) in equation (2).
3x+420-x=720
2x=720-420
2x=300
⇒x=150
Put the value of x in equation (1)
y=420-150
⇒y=270
So, there are 150 adults and 270 children visited.