Answer:
cost of one medium drink = $3.80
cost of one large popcorn = $6.25
Step-by-step explanation:
Let D = cost of one medium drink
Let P = cost of one large popcorn
If a couple bought 2 medium drinks and a large popcorn for $13.85:
⇒ 2D + P = 13.85
If a family bought 3 medium drinks and 2 large popcorn for a total of $23.90:
⇒ 3D + 2P = 23.90
Rewrite 2D + P = 13.85 to make P the subject:
⇒ P = 13.85 - 2D
Substitute into 3D + 2P = 23.90 and solve for D:
⇒ 3D + 2(13.85 - 2D) = 23.90
⇒ 3D + 27.7 - 4D = 23.90
⇒ D = 3.8
Substitute found value of D into P = 13.85 - 2D to find P:
⇒ P = 13.85 - (2 x 3.8) = 6.25
Therefore,
cost of one medium drink = $3.80
cost of one large popcorn = $6.25
