Selena is planning a birthday party for her little sister at a local zoo. The price depends on the number of children that atten
d the party. The price per child is normally $7. However, if there are more than 10 children in a group, the group can pay a $20 fee plus $4 per child. Which piecewise-defined function best models the cost of the party c(x) if Selena invites x children?
