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

Question

3 years ago

10

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

Mathematics

2 answers:

11111nata11111 [884] · Answer 1 · 2022-03-21T11:33:06+03:00

11111nata11111 [884]3 years ago

8 0

a+c=40

c=40-a

11c +20a=728

11(40-a)+20a=728

440-11a +20a=728

440+9a=728

9a = 288

a=288/9 = 32

32 adults

8 children

kherson [118] · Answer 2 · 2022-03-21T12:57:10+03:00

A + c = 40
20a + 11c = 728

Multiply equation # 1 by -11, then add the two equations together to clear the 'c' variable and solve for 'a'.

-11(a + c = 40)

20a + 11c = 728
-11a - 11c = -440
------------------------
9a = 288
Divide both sides by 9
a = 32

a + c = 40
32 + c = 40
subtract 32 from both sides
c = 8

8 children and 32 adults; option 1