A house has three tube lights, two fans and a Television. Each tube light draws 40W. The fan draws 80W and the Television draws 60W. On the average, all the tube lights are kept on for five hours, two fans for 12 hours and the television for five hours every day. Find the cost of electric energy used in 30 days at the rate of Rs. 3.00 per KWH.
Answers
Electric energy of 3lights is 3*40*5*30
=18000w
Electric energy of 2 Fans =2*80*12*30
=57600w
Electric energy of a TV=1*60*5*30
=9000w
These all are in Watts we have to convert them into Kilo Watts
1kw=1000w
3 light cost =18000/1000*3
=18*3
=54Kw
2 Fans cost=57600/1000*3
=57.6*3
=172.8kw
1 tv cost=9000/1000*3
=9*3
=27kw
Electric bill cost is 54+172.8+27
=258.3/-
Therefore Electric bill cost is 258.3/-
Answer:
Total cost of electric energy used for 30 days is = Rs. 253.8/-
Explanation:
Given,
ITEMS Number of units( 1 unit =1000WATTS) Hours used 3 TUBE LIGHTS 40/1000=0.04 5hrs/ 1day
2 FANS 80/1000=0.08 12hrs/1day
1 TELEVISION 60/1000=0.06 5hrs/1day
step-1 => for 3 tube lights
5 x 40/1000 x 3 = 15 x 0.04 = 0.6 => for 30 days = 0.6 x 30 = 18
step-2 => for 2 fans
12 x 80/1000 x 2 = 24 x 0.08 = 1.92=> for 30 days = 1.92 x 30 = 57.6
step-3 => for 1 television
5 x 60/1000 x 1 = 5 x 0.06 = 0.3 => for 30 days = 0.3 x 30 = 9
*hence,
Total cost of electric energy used = total number of units x cost per unit
=> total cost = 18 + 57.6 + 9 x 3 = 84.6 x 3 = 253.8