In a house 3 bulbs of 25 W each are used for 5 h a day. Calculate the units of electricity consumed in a month of 31 days. Also, find the total expenditure, if 1 unit of electricity costsRs 2.50.

Given, power of each bulb = 25 W, time = 5 h Cost of 1 unit of electricity = Rs 2.50 Electric energy consumed by 3 bulbs in a .day = Power x Time = 3 x 25 = 375Wh

Electricity consumed in 31 days = 375 x 31 = 11625 Wh

=11.625kWh = 11.625 units

Cost of Electricity consumed = 11.625 x 2.50 = Rs 29.06