A house has 3 tube lights, two fans and a Television

A house has 3 tube lights, two fans and a Television. Each tube light draws 40W. The fan draws 80 W and the Television draws 60W. On the average, all the tube lights are kept on for five hours, two fans for 12 hours and the television for five hours every day. Find the cost of electric energy used in 30 days at the rate of Rs. 3.00 per Kwh.

Given 3 tube lights, two fans and a television.
1 tube light consumes power = 40 W
There fore ,3 tube lights consume power = 3 x 40 W= 120 W
3 tube lights are kept on for five hours. So, consumption of power by 3 tube lights.
= 5 x 120 W = 600 W-------(1)
1 fan consumes power = 80 W
Therefore, 2 fans consume power = 2 x 80 W= 160 W 2 fans are kept on for 12 hours. So, consumption of power by 2 fans.
= 12 x 160 W = 1920 W-----------(2)
TV draws power = 60 W
TV is kept on for 5 hours = 5 x 60 W = 300 W---------(3)
Therefore, In One day consumption of power = (1) + (2) + (3)
= 600 W + 1920 W + 300 W
= 2820 W = 2.820 KW
Therefore, Total consumption of power in 30 days at Rs. 3 per KW
= 2.820 x 30 x 3 = Rs. 253.80