Question

Two smoothies and an ice cream cone cost $7.50. Three smoothies and two ice cream cones cost $12. Calculate the cost of a smoothie and the cost of an ice cream cone.

Answer 1

Smoothie = 3

Ice cream = 1.5

Explanation:

2s + i = 7.5

3s + 2i = 12

subtract the equations

(3s + 2i) - (2s + i) = s + i

s + i = 4.5

2s + i = 7.5, so s must equal 3 (7.5 - 4.5)

If s = 3, then i is 1.5 (4.5 - 3.5)

To check, plug 3 and 1.5 into s and i.

2(3) + 1.5 = 7.5

6 + 1.5 = 7.5

7.5 = 7.5

3(3) + 2(1.5) = 12

9 + 3 = 12

12 = 12