two bulbs A and B are rated 100W-120V and 10W-120V respectively..they are connected across a 120V..

The energy consumed by a bulb is i² R.

Using the information given first find the resistance of each bulb which can be found using P = V²/R.

Then simply consider two resistors connected in series and find the current in the circuit. Next find energy in each bulb.

At times to keep the calculation easy do not simplify completely at each step. For instance write the resistance of the 100W 120V bulb as (120²/100) and use it in this form while doing calculations.

Try solving the question and let me know at which step do you have trouble solving further.