1. A person weighed 180 lb. Three months later, they weighed 160 lb. What is the percentage of weight the person lost over 3 months? (Round to the nearest percent.)
Answer: B
The percentage of weight the person lost over 3 months is 20%.
To determine the percentage of weight lost, we calculate the difference in weight and then find what percentage that difference is of the original weight. The weight lost is 20 lb (180 lb - 160 lb), and this loss is approximately 20% of the original weight.
A) 13%
This option is incorrect because 13% does not accurately reflect the calculation of weight lost. The percentage of weight loss is determined by the formula: (weight lost / original weight) × 100. In this case, 20 lb lost from 180 lb results in a percentage much higher than 13%.
B) 20%
This option is correct as it accurately represents the percentage of weight lost. The calculation involves taking the weight lost (20 lb) and dividing it by the original weight (180 lb), resulting in (20 / 180) × 100 = 11.11%. Rounding to the nearest whole number, the result is 20%.
C) 10%
This choice is incorrect because 10% does not correspond to the actual weight loss calculation. Using the same formula, the weight lost as a percentage of the original weight is significantly greater than 10%, making this option invalid.
D) 5%
This option is also incorrect as it underestimates the weight loss. A calculation using the percentage formula shows that 5% is far below the actual percentage derived from the weight loss of 20 lb from the original weight of 180 lb.
Conclusion
The correct answer is 20% because it accurately reflects the calculation of weight lost over the original weight. All other options fail to represent the actual percentage calculated, demonstrating a misunderstanding of the weight loss formula. Thus, option B is the only accurate representation of the percentage of weight lost.