Resistance, Resistivity, and Ohm's Law Practice Test

Wire A has length $$L$$ and radius $$r$$. Wire B, made from the same uniform material, has length $$2L$$ and radius $$r/2$$. What is the ratio of the resistance of Wire B to the resistance of Wire A, $$R_B/R_A$$?

The potential difference $$V$$ across a circuit component is measured as a function of the current $$I$$ through it. A plot of $$V$$ as a function of $$I$$ results in a straight line passing through the origin with a slope of $$200,\text{V/A}$$. What is the resistance of the component?