Question Detail
Question
Two resistances R1 and R2 give a combined resistance of 4.5Ω when in series and 1Ω when in parallel. What are the resistances?
Correct Answer
Option C is the correct answer.
Detailed Explanation
Solving R1+R2=4.5 and R1R2/(R1+R2)=1 (so R1R2=4.5) as a quadratic gives roots 1.5Ω and 3Ω.
Hint
Set up two equations from the series and parallel formulas, then solve them as a quadratic.