Question

Josh bought 3 bottles of grape juice and 5 bottles of water for a total of $14.50. Mary bought 2 bottles

of grape juice and 3 bottles of water for a total of $9.00. How much does the grape juice cost and the water?

Answer 1

• Bottle of water = $2
• Bottle of grape juice = $1.50

Explanation:

• Grape juice = g
• Water = w

Equations:

• 3g + 5w = 14.50
• 2g + 3w = 9.00

Subtract the 3 times the second equation from the twice the first:

• 2*(3g + 5w) - 3(2g + 3w) = 2*14.50 - 3*9.00
• 6g + 10w - 6g - 9w = 29 - 27
• w = 2

Then, finding g:

• 3g + 2*5= 14.50
• 3g = 14.50 - 10
• 3g = 4.5
• g = 1.50