A family went out to see a movie. The regular ticket costs $9 and the ticket for children is $2 less. They gave the cashier two $20 bills and they received a $1 change. How many children are there if there are 2 adults in the family?
They gave the cashier $20 x 2 = $<T>multiply(20, 2)=40
Since a $1 change was returned, this means the tickets cost $40 - $1 = $<T>subtract(40, 1)=39
Two adult tickets cost $9 x 2 = $<T>multiply(9, 2)=18
So, $39 - $18 = $<T>subtract(39, 18)=21 was spent for the children's tickets.
Each child's ticket costs $9 - $2 = $<T>subtract(9, 2)=7
Therefore, there are $21/$7 = <T>divide(21, 7)=3.0 children.
