The regular admission price for an amusement park is $72. For a group of 15 or more, the admission price is reduced by $25. How many people need to be in a group to save $500?
$500 / $25 =20 groups of 15 people or more.
A minimum of 15 people x 20 groups = 300 people to save $500.
If admission price is REDUCED by $25/person if the group is fifteen or more:
$500 / $25/person = 20 people would 'save' $500 over the original admission price.