Step-by-step explanation:
The voltage of the lamp, V = 240 V
Power of the lamp, P = 40 W
It is running for 62 hours.
The cost of running is $2.50k per KWH
Electric power is,
P = 40×62 Wh
= 2480 Wh
P = 2.48 kWh
At the rate of $2.5 per kWh
P = $6.2
So, the cost of running is $6.2 per kWh.