Question

The admission fee at a zoo is $2 for children and $4 for adults. If 1800 people enter the zoo and $6000 is collected, how many adults went to the zoo?

Answer 1

The number of adults is
`1,200`

Explanation:

Let

x------> the number of children

y------> the number of adults

we know that

`x+y=1800` -------> equation A

`2x+4y=6000` -------> equation B

Multiply equation A by
`-2`

`-2(x+y)=-2*1800` -------->
`-2x-2y=-3600` ------> equation C

Adds equation B and equation C

`2x+4y=6000\\-2x-2y=-3600\\---------\\4y-2y=6000-3600\\2y=2400\\y=2400/2\\y=1200`

Answer 2

x= adult, y = kid

x+y=1800

4x+2y=6000

x=1800-y now put that into the 2nd equation

4(1800-y)+2y=6000

7200-4y+2y=6000

4y-2y=7200-6000

2y=1200

y=600

x=1800-600 = 1200

so 1200 adults and 600 kids