When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them

20 watt

$\text{Let Resistance of each bulb is R} P = \frac{V_0^2}{R}$ 

$\text{ Since Three bulbs are similar Voltage across each bulb is }\frac{V_0}{3}$

$ P_1 = \frac{V_0^2}{9R}$

$ P = 3P_1 = \frac{V_0^2}{3R} = \frac{P}{3} = \frac{60}{3} = 20W$