Question

A customer comes to the hardware store where you work. he wants to know how much concrete mix he needs to pour a four-inch slab for his patio. he knows that the length of the patio is 66 inches and the width is 4 feet. you need to know the area to answer his question. the customer calculates the area as a = (66)(4) = 264 square feet. is this correct?

A. the calculation and units are correct.
B. the calculation is correct, but the units should be square inches.
C. no, the calculation should be a = (66)(48) = 3,168 square feet.
D. no, the calculation should be a = (5.5)(4) = 22 square inches.
E. no, the calculation should be a = (5.5)(4) = 22 square feet.

Answer 1

The customer's calculation of the area for a four-inch slab was incorrect due to a mix-up in units. The correct calculation should be area = length × width = 66 inches × 48 inches, resulting in 3,168 square inches or 22 square feet (option C).

Step-by-step explanation:

The customer's calculation for the area of the patio is incorrect. The mistake lies in not converting all dimensions to the same units before calculating the area. The width is given in feet and needs to be converted to inches to match the units of the length. There are 12 inches in a foot, so the width in inches is 4 feet × 12 inches/foot = 48 inches. Therefore, the correct calculation is area (A) = length × width = 66 inches × 48 inches.

This results in A = 3168 square inches. To express the area in square feet, we can divide by the conversion factor (since there are 144 square inches in a square foot). Thus, the area in square feet is 3168 square inches ÷ 144 square inches/square foot = 22 square feet.

So the correct answer is C: no, the calculation should be a = (66)(48) = 3,168 square feet. Remember to always verify the consistency of units when performing calculations involving measurements.