Question

at a concession stand, seven hot dog(s) and four hamburger(s) cost $18.25; four hot dog(s) and seven hamburger(s) cost $17.50. Find the cost of one hot dog and the cost of one hamburger. What is the cost of one hot dog?

Answer 1

The cost of one hot dog is $1.75

The cost of one hamburger is $1.5

Explanation:

Let,

• The cost of hot dog be 'x'.
• The cost of hamburger be 'y'.

The equations can be formed as :

7x + 4y = 18.25 --------(1)

4x + 7y = 17.50 --------(2)

Multiply eq (1) by 4 and eq (2) by 7,

28x + 16y = 73

- (28x + 49y = 122.5)

- 33y = - 49.5

y = 49.5/33

y = 1.5

The cost of one hamburger is $1.5

Substitute y=1.5 in eq (1),

7x + 4(1.5) = 18.25

7x = 18.25 - 6

x = 12.25/7

x = 1.75

The cost of one hot dog is $1.75