Question

Calculate the electricity bill amount for a month of 31 days, if the following devices are used as specified :

(a) 3 bulbs of 40 W for 6 hours.

(b) 4 tube lights of 50 W for 8 hours,

(c) A TV of 120 W for 6 hours.

Give the rate of electricity is Rs 2.50 per unit

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Answer 1

kwh= 3 × 40 × 6 + 4 × 50 × 8 + 120 × 6

kwh= 720 + 1600 + 720 = 3040 in one day

for 31 day electricity is used by appliances are

3040 × 31 = 94240 kwh

in unit power is 1000w in 1h

so, 94240 ÷ 1000 = 94.24 kw/h

the rate of electricity is Rs 2.50 per unit

electricity bill for a month is 2.50 × 94.20 = Rs 235.6