Question

Mary spent a total of $322.78 for a party. She spent $200.66 on food, plus an additional $30.53 for each hour of the party. How long was the party?

Answer 1

Let h equal the length of the party in hours

200.66 + 30.53h = 322.78

now just solve for h :)
30.53h = 122.12
h = 4

so the party was 4 hours long

Answer 2

4 hours because you have to first subtract 322.78 and 200.66 then whatever you get you divide that by 30.53