Answer:
If the resistors are in series the current thru the circuit will be the same for all of the resistors,
Normally, the value of a resistor is given in ohms but the question seems to imply that resistance is given in watts.
3900 + 1000 + 100 = 5000 watts total power used in the circuit
P = I V
5000 = I * 200 volts
I = 25 amps
So I^2 R = 1000 watts for the named resistor
R = 1000 / 25^2 = 1.6 ohms for the 1000 watt resistor
V = I * R = 25 amps * 1.6 ohms = 40 V across that resistor
Check: 3900 / 1000 * 40 = 156 volts
100 / 1000 * 40 = 4 volts
Total voltage drop = 40 + 156 + 4 = 200 volts as given