Question

Suppose in a house there are four bulbs of 100 W each, six of 60 W each and six of 40 W each. All of them are used for two hours a day. How many units of electricity will be used up in 30 days? How much will they have to pay at Rs. 2.80/- per unit.

Answer 1

1. Total power used = (4 × 100 W) + (6 × 60 W) + (6 × 40 W) = 1000 W = 1 KW 

2. Total power used every day = 2 hrs × 1 KW = 2 KWH In 30 days, power used = 2 × 30 KWH = 60 KWH 

3. The cost of the power is = Rs. 2.80 × 60 = Rs. 168/-