SOLUTION: The utility company charges 14 cents per kwh. What is the daily cost of keeping (a) an 8 watt lightbulb on for 8 hours? (b) If a regular lightbulb is 60 watts, how much will you

Algebra ->  Decimal-numbers -> SOLUTION: The utility company charges 14 cents per kwh. What is the daily cost of keeping (a) an 8 watt lightbulb on for 8 hours? (b) If a regular lightbulb is 60 watts, how much will you       Log On


   

Question 906714: The utility company charges 14 cents per kwh. What is the daily cost of keeping (a) an 8 watt lightbulb on for 8 hours?
(b) If a regular lightbulb is 60 watts, how much will you save for 30 days if you use it for 8 hours a day?
Found 2 solutions by CubeyThePenguin, ikleyn:
Answer by CubeyThePenguin(3113) About Me  (Show Source):
You can put this solution on YOUR website!
(8 W)(8 hr) = 64 Wh = 0.064 kWh = 89.6 cents

regular bulb: (60 W)(8 * 30 hr) = $14.88

Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
.
The utility company charges 14 cents per kwh. What is the daily cost of keeping (a) an 8 watt lightbulb on for 8 hours?
(b) If a regular lightbulb is 60 watts, how much will you save for 30 days if you use it for 8 hours a day?
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            These simple calculations are presented in the post by @CubeyThePenguin in some absurdist manner,
            so I even can not read it and can not dispose them in the order in my mind.

            THEREFORE,  I redone the calculations in more organized way.   See below. 


(a)  Consumed energy daily     = 8 watt * 8 hours = 64 wt*h = 0.064 kwh.

     Daily cost                = 14 cents * 0.064 kwh = 0.896 cents.    

     Monthly cost              = 0.896 cents * 30 days = 26.88 cents = 27 cents (rounded)



(b)  Consumed energy (monthly) = 60 watt * 8 hours * 30 days = 14400 wt*h = 14.4 kwh.

     Monthly cost              = 14 cents * 14.4 kwh = 26.88 cents = 201.6 cents = 202 cents (rounded).



You save  202 cents - 27 cents =  175 cents = $1.75 monthly.

Solved // (correctly)