Final answer:
Milliliters and millimeters cannot be added together after conversion, as milliliters measure volume and millimeters measure length. Other pairs like miles and kilometers, grams and kilograms, and kilometers and inches are compatible for conversion and addition as they represent the same quantity type. The correct answer is b) milliLiters and millimeters.
Step-by-step explanation:
The pair of units that may not be added together, even after the appropriate unit conversions have been made, are milliliters (mL) and millimeters (mm). This is because milliliters are a unit of volume, while millimeters are a unit of length, and these two types of quantities are not compatible for direct addition.
For unit conversions, the following conversion factors exist between some given units:
- Kilograms and grams: 1 kilogram = 1000 grams
- Milliseconds and seconds: 1 second = 1000 milliseconds
- Centimeters and meters: 1 meter = 100 centimeters
- Milliliters and liters: 1 liter = 1000 milliliters
Therefore, miles and kilometers, grams and kilograms, kilometers and inches can all be converted to one another and added because they measure the same quantity type - either length or mass. However, milliliters and millimeters cannot be directly added even after conversion because they measure different types of quantities - volume and length respectively.