Question

Saturday morning there were 7 adults and 20 kids at Pump and Jump Land. The morning cash registers show $236 was collected. In the afternoon there were 21 adults and 50 kids for a total amount of $618. What is the cost for 1 adult?

Answer 1

The cost of one adult is $8

Explanation:

Let

x-----> the cost for one adult

y ----> the cost for one kid

we know that

`7x+20y=236` -------> equation A

`21x+50y=618` -------> equation B

Solve the system by elimination

Multiply the equation A by -2.5 both sides

`-2.5(7x+20y)=236(-2.5)`

`-17.5x-50y=-590` -----> equation C

Adds equation B and equation C and solve for x

`21x+50y=618\\-17.5x-50y=-590\\-----------\\21x-17.5x=618-590\\3.5x=28\\x=\$8`

therefore

The cost of one adult is $8