Two electric bulbs rated P1 and P2 watt at V volt are connected in series across V volt mains, then their total power consumption P is:

Resistance of Ist bulb =R1=V2P1Resistance of IInd bulb =R2=V2P2When both bulbs are connected in series,Req.=V21P1+1P2=V2P1+P2P1P2Hence, power consumed P=V2R                                           =V2V2P1+P2P1P2=P1P2P1+P2                                         Hence, (c) is correct.