Answer:
So the mass of the second object M will be 1.951 kg
Explanation:
We have given mass of the first object
and its velocity 
Mass of the second object
it is at rest so its velocity 
From conservation of momentum we know that
Initial momentum = final momentum
So 


M = 1.951 kg
(5 bulbs) x (25 watt/bulb) x (6 hour/day) x (30 day/month) =
(5 x 25 x 6 x 30) watt-hour/month =
22,500 watt-hour/month .
The most common unit of electrical energy used for billing purposes
is the 'kilowatt-hour' = 1,000 watt-hours .
22,500 watt-hour/month = <em>22.5 kWh/month</em>.
(22.5 kWh/month) x (1.50 Rs/kWh) = <em>33.75 Rs / month
</em>
I have no idea what that is, but all of your answers right
The mass of the object is the answer of your question