What is the voltage across the resistor

When the voltage across the resistor is 160 V, the current equals .600 A.

(a) What is the voltage when the voltage across the resistor is .800 A?

(b) What is the current when the voltage across the resistor is 250 V?

R = (E/I) = (160/0.6) = 266.67 ohms.
a) E = (IR), = 0.8 x 266.67, = 213.336V.
b) I = (E/R), = 250/266.67, = 0.937A.