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A delivery firm works out a rate of change using cost in pounds as the output and the number of parcels as the input. What units does that rate carry?
AParcels per hour
BPounds per pound
CPounds per parcel
DParcels per pound
Answer & Solution
Correct answer: C. Pounds per parcel
1. A rate of change is the change in output divided by the change in input.
2. Dividing pounds by parcels leaves units of pounds for each one parcel.
3. Option D turns the division upside down, which would answer a different question.
4. So the rate carries units of pounds per parcel, option C.
_Source: OpenStax College Algebra (CC BY 4.0), Ch 4 "Linear Functions", section 4.1 Linear Functions_
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