At the produce counter, $71/5$ pounds of seedless grapes cost $12.89. How much would 3 pounds cost?
A) $3.58
B) $5.16
C) $5.37
D) $1.79
Answer (1)
Calculate the price per pound of grapes: 71/5 12.89 = 71 64.45 .
Multiply the price per pound by 3 to find the cost of 3 pounds: 3 × 71 64.45 = 71 193.35 .
Calculate the cost of 3 pounds: 71 193.35 ≈ 2.7232 .
Round the result to the nearest cent: $2.72 . Since this is not an option, we conclude there may be an error in the options.
Explanation
Understanding the Problem We are given that 71/5 pounds of seedless grapes cost $12.89 . We want to find the cost of 3 pounds of the same grapes.
Calculating Price per Pound First, we need to find the price per pound of the grapes. To do this, we divide the total cost by the total weight: Price per pound = Total weight Total cost = 71/5 12.89 Price per pound = 14.2 12.89 ≈ 0.9077
Calculating Cost of 3 Pounds Now that we have the price per pound, we can find the cost of 3 pounds of grapes by multiplying the price per pound by 3: Cost of 3 pounds = Price per pound × 3 = 0.9077 × 3 ≈ 2.7232 Rounding to the nearest cent, the cost of 3 pounds of grapes is $2.72 .
Re-calculating with Fractions However, the options provided do not include $2.72 . Let's re-calculate the price per pound and the cost of 3 pounds using fractions to avoid rounding errors until the end. The price per pound is: 5 71 12.89 = 71 12.89 × 5 = 71 64.45 Cost of 3 pounds = 3 × 71 64.45 = 71 193.35 ≈ 2.723239 Rounding to the nearest cent, the cost of 3 pounds of grapes is $2.72 .
Analyzing the Options Since $2.72 is not among the options, let's examine the given options to see if there was an error in the problem statement or the options themselves. The closest option to our calculated value is A) $3.58 , B) $5.16 , C) $5.37 , D) $1.79 . None of these options are close to $2.72 . Therefore, there might be an error in the problem statement or the options. However, based on our calculations, the cost of 3 pounds of grapes is approximately $2.72 .
Final Calculation and Conclusion Let's recalculate the exact value without rounding until the very end: Price per pound = 5 71 12.89 = 71 12.89 × 5 = 71 64.45 Cost of 3 pounds = 3 × 71 64.45 = 71 193.35 ≈ 2.7232394366 Rounding to two decimal places, we get $2.72 . Since this is not an option, we must assume there is an error in the provided options.
Examples
Understanding unit prices helps consumers make informed purchasing decisions. For example, if you are comparing two different sizes of the same product, calculating the price per unit (e.g., per pound, per ounce) allows you to determine which size offers the better value. This is particularly useful when shopping for groceries or other household items where products are sold in various quantities and at different prices. By calculating the unit price, you can effectively compare the cost and choose the most economical option, saving money in the long run.
