Question

The Montoya family and the Cooper family are seeing a movie together in the theater. At the concession stand, Mr. Montoya paid $20 for 3 large popcorns and 1 large drink that his family will share. Mrs. Cooper bought 3 large popcorns and 3 large drinks and paid $30. How much does each item cost?

Answer 1

Both items cost $5 each

Explanation:

Given data

let popcorn be x

and drink be y

Mr. Montoya paid $20 for 3 large popcorns and 1 large drink

so

3x+y= 20-------------1

and

Mrs. Cooper bought 3 large popcorns and 3 large drinks and paid $30

so

3x+3y= 30----------------2

solve 1 and 2 above

3x+y= 20

y= 20-3x

put y= 20-3x in eqn 2

3x+3(20-3x)= 30

3x+60-9x= 30

collect like terms

3x-9x= 30-60

-6x= -30

x= 30/6

x= $5

put x= 5 in y= 20-3x

y= 20-3*5

y= 20-15

y= $5