Figure $27-27$ shows a circuit of four resistors that are connected to a larger circuit. The graph below the circuit shows the electric potential $V(x)$ as a function of position $x$ along the lower branch of the circuit, through resistor 4 ; the potential $V_{A}$ is 12.0 $\mathrm{V}$ . The graph above the circuit shows the electric potential $V(x)$ versus position $x$ along the upper branch of the circuit, through resistors $1,2,$ and $3 ;$ the potential differences are $\Delta V_{B}=2.00 \mathrm{V}$ and $\Delta V_{C}=5.00 \mathrm{V} .$ Resistor 3 has a resistance of 200$\Omega .$ What is the resistance of (a) resistor 1 and (b) resistor 2?