In the circuit shown in figure, V must be

50 V 80 V 100 V 1290 V

80 V

In the circuit, we can see that 20Ω, 100Ω and 25Ω are in parallel. Net resistance of circuit = $4+6+\frac{1}{\frac{1}{20}+\frac{1}{100}+\frac{1}{25}}$ = 20Ω ∴   V = iR = 4 × 20 = 80 V