How would one convert 125 lb to kilograms $(1 oz =28 g)$?
A. $125 lb \times \frac{16 oz }{1 lb } \times \frac{28 g}{1 oz } \times \frac{1 kg}{1000 g}$
B. $125 lb \times \frac{28 g}{1 oz }$
C. $125 lb \times \frac{16 oz }{1 lb } \times \frac{28 g}{1 oz }$
D. $125 lb \times \frac{28 g}{1 oz } \times \frac{1 kg}{1000 g}$
Answer (1)
Convert pounds to ounces using the conversion factor 1 l b 16 oz .
Convert ounces to grams using the conversion factor 1 oz 28 g .
Convert grams to kilograms using the conversion factor 1000 g 1 k g .
The correct expression for the conversion is 125 l b × 1 l b 16 oz × 1 oz 28 g × 1000 g 1 k g , which corresponds to option A.
The final answer is A .
Explanation
Problem Analysis We are asked to convert 125 lb to kilograms, given that 1 oz = 28 g. To do this, we need to use the correct conversion factors to cancel out the units and arrive at the desired unit (kilograms).
Pounds to Ounces First, we need to convert pounds (lb) to ounces (oz). We know that 1 lb = 16 oz. So, we multiply 125 lb by the conversion factor 1 l b 16 oz .
Ounces to Grams Next, we convert ounces (oz) to grams (g). We are given that 1 oz = 28 g. So, we multiply the result from the previous step by the conversion factor 1 oz 28 g .
Grams to Kilograms Finally, we convert grams (g) to kilograms (kg). We know that 1 kg = 1000 g. So, we multiply the result from the previous step by the conversion factor 1000 g 1 k g .
Complete Conversion Expression Combining all the conversion factors, we get the following expression: 125 l b × 1 l b 16 oz × 1 oz 28 g × 1000 g 1 k g
Final Answer Comparing this expression with the given options, we see that option A matches our derived expression. Therefore, the correct answer is: 125 l b × 1 l b 16 oz × 1 oz 28 g × 1000 g 1 k g
Examples
Imagine you're baking a cake using a recipe from another country that uses metric units, but your kitchen scale only measures in pounds. Converting the ingredient amounts from pounds to grams or kilograms is essential to ensure the cake turns out correctly. This conversion process, similar to the problem we solved, allows you to accurately measure ingredients and follow the recipe successfully. Understanding unit conversions is also crucial in fields like medicine, engineering, and manufacturing, where precise measurements are vital for safety and quality.
