Question

${ \bf \underline {Question}}\downarrow$

In a school there are 10 electric fans each of 40 W runs for 5 hours a day, 5 electric lamps each of 60 W runs for 3 hour daily. If the cost of each unit of electricity be Rs. 5, then calculate the monthly cost for electricity.

☆ Quality answer needed.
☆ Don't spam.

THANK YOU​

Answer 1

Energy consumed by

fans=10×40×5

=2000 Wh

lamps=5×60×3

=900Wh

Total electrical energy per day=2900Wh

Hence 2.9 kWh

Total electrical energy for 30 days= 2.9×30

=87 kWh

Cost=87×5

=₹435

Hope it helps pal ☺☺

Answer 2

Given:

In a school there are 10 electric fans each of 40 W runs for 5 hours a day, 5 electric lamps each of 60 W runs for 3 hour daily.

To find:

Total monthly cost ?

Calculation:

First of all, we need to calculate the total units of electricity used in a month.

Total energy used per day :

• For fans: 10 × (40 × 5) = 2000 W hr

• For light: 5 × (60 × 3) = 900 W hr

Hence , total energy per day :

$\therefore \: E_{daily} = 2000 + 900 = 2900 \: W \: hr$

$\implies\: E_{daily} = 2.9 \: kW \: hr$

$\implies\: E_{daily} = 2.9 \: units$

Total energy in a month:

$\implies\: E_{month} =( 2.9 \times 30)\: units$

$\implies\: E_{month} =87\: units$

Total cost in a month:

$\implies\: Cost_{month} = Rs(87 \times 5)$

$\implies\: Cost_{month} = Rs \: 435$

So, total cost is ₹ 435.