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

power of 1 electric bulb = 25 W

= 0.25 W

3 electric bulb = 0.25*3

= 0.75

time = 5 h

energy = power * Time taken

= 0.75*5

Energy consumed will be = 3.75 units

In 1 day it will be = 3.75

in 31 day = 3.75*31

= 116.25 units

Cost

1 units = 2.50 Rs

116.25 units = 116.25*2.50

Cost will be = 290.625 Rs

power of 1 electric bulb = 25 W

= 0.25 kW

3 electric bulb = 0.25*3

= 0.75 kW

time = 5 h

energy = power * Time taken

= 0.75*5

Energy consumed will be = 3.75 units

In 1 day it will be = 3.75

in 31 day = 3.75*31

= 116.25 units

Cost

1 units = 2.50 Rs

116.25 units = 116.25*2.50

Cost will be = 290.625 Rs