Question

A restaurant catered a party for 40 people. A child’s dinner (c) cost $11 and an adult’s dinner (a) cost $20. The total cost of the dinner was $728. How many children and adults were at the party? Use the table to guess and check. 8 children and 32 adults 9 children and 31 adults 10 children and 30 adults 12 children and 28 adults

Answer 1

x=8 number of children

y=32 number of adults

Explanation:

x be children and y for adults

x+y=40 ⇒ y=40-x

11x+20y=728 solve by substitution of y=40-x

11x+20(40-x)=728

11x+800-20x=728

-9x=728-800

x=72/9 ⇒ x=8 number of children

y=40-x

y=40-8⇒ y=32 number of adults