Which is the better buy?

Question

5-yard roll of aluminum foil for$7.20.
95-inch roll of aluminum foil for $5.70

Answer 1

To determine which aluminum foil option is the better buy, we can calculate the cost per square inch for each roll.

1. 5-yard roll:

   • 1 yard = 36 inches, so 5 yards = 5 × 36 = 180 inches.
   • The width of standard aluminum foil is generally 12 inches.
   • Area = Length × Width = 180 inches × 12 inches = 2160 square inches.
   • Cost = $7.20.
   • Cost per square inch = \( \frac{7.20}{2160} \approx 0.00333 \) dollars per square inch.

2. 95-inch roll:

   • Area = Length × Width = 95 inches × 12 inches = 1140 square inches.
   • Cost = $5.70.
   • Cost per square inch = \( \frac{5.70}{1140} \approx 0.00500 \) dollars per square inch.

Comparing the two:

• The 5-yard roll costs approximately $0.00333 per square inch.
• The 95-inch roll costs approximately $0.00500 per square inch.

Conclusion: The 5-yard roll of aluminum foil for $7.20 is the better buy, as it has a lower cost per square inch.