Question

7. An electric bulb rated 60 W is used 10 hours
per day for 20 days. If the cost of a unit is
3.00. find the energy bill. (Ans. 36)
8. Two electric bulbs rated 60 W and 40 W
respectively are used 5 hours per day for
20 days. If the cost of a unit is * 4.00, find the
cost of the energy used.
(Ans. 40)​

Answer 1

Answer:

Power= 60 Watt

Everyday Use = 10 Hours

Total Days= 30

Cost Of elctricity per unit= 3.50 Rs.

Find:-

Total amount to be paid in 30 days

Given:-

The days can be calculated in total hours used in 30 days

Hence, Days x Everyday Use = 30 x 10 = 300 Hours

Convert, 60 Watt into Kwatt = 60/1000

By Formula,

Unit= Kwatt x Time (in hours)

U= 60/1000 x 300

U= 18

Hence, total unit used is 18.

By Formula,

Cost= Unit x Rupees per unit

Cost= 18 x 3.50

Cost= 63 Rupees