GED Math Help: percents

To rent a hall for a party reception (for 1 evening) costs $225. The Hall is also charging $25.50 per adult and $19.95 per child for the meal and reception. Gratuity is 15% of total costs. If 125 adults and 32 children attending the party, what is the total cost.... including gratuity?

Answer: Set up the problem as follows:

First part: (cost of hall + (cost of adult meal)(number of adults attending)+ (cost of child meal)(number of children attending)
Second part: 15% of (cost of hall + (cost of adult meal)(number of adults attending)+ (cost of child meal)(number of children attending)
.
Find the answers to part one and two, and then add them together.
.
Part one- hall and meals: $225 + (125 x $25.50) + (32 x $19.95) = $4050.90.
Part two- gratutity: .15 x $4050.90 = $607.34
.
Total cost: $4050.90 + $607.34 = $4658.24

Have you recently held a reception? How did you calculate costs?