Peak Voltage (also known as max Voltage) is given by:

Vmax = Vrms * √2

Part B:

You can solve for the resitance by relating power with voltage and resistance:

Power = Vrms^2 / Resistance

Part C:

a 100-W bulb has less resistance than a 60-W bulb, looking at the equation for power, less resistance equals greater power for the same amount of voltage.