Question

Noah went into a movie theater and bought 9 drinks and 4 candies, costing a total of $60. Nachelle went into the same movie theater and bought 10 drinks and 2 candies, costing a total of $57.50. Determine the price of each drink and the price of each candy.

Answer 1

Drink: $5

Candy : $3.75

Explanation:

Let d = the cost of a drink

Let c = the cost of a candy

9d + 4c = 60

10d + 2c = 57.50 ⇒ Mult. by -2 ⇒ -20d -4c = -115 Add this to the first equation

-20d - 4c = -115

9d + 4c = 60

-11d = -55 Divide both sides by -11

d = 5

A drink costs $5.00.

Plug in 5 for d in either of the two equations to solve for c

9d + 4c = 60

9(5) + 4x = 60

45 + 4c = 60 Subtract 45 from both sides

4c = 15 Divide both sides by 4

x = 3.75

A candy costs $3.75