## An electric water heater consumes 2.5 kW for 1.9 h per day. What is the cost (in $) of running it for one year if electricity costs 1 Question An electric water heater consumes 2.5 kW for 1.9 h per day. What is the cost (in$) of running it for one year if electricity costs 11.5 cents/kWh?

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10 hours 2021-07-21T22:16:40+00:00 1 Answers 0 views 0

The cost of running the electric water heater for one year is 55.2391 $Explanation: The simple rule of 3 helps to quickly solve proportionality problems when you have three known values ​​and one unknown. If two quantities are directly proportional (that is, when multiplying or dividing one of them by a number, the other is multiplied or divided respectively by the same number) the rule of three can be applied as follows: a ⇒ b c ⇒ x So: where a, b and c are the known values ​​and x is the value you want to find out. In this case, you can first apply the following rule of three: if 2.5 kW are consumed in 1.9 hours, in 1 hour how many kW are consumed? kWh=1.316 So an electric water heater consumes 1.316 kWh in one day. You apply another simple rule of three: if the heater in 1 day consumes 1.316 kWh, in 365 days (1 year) how many kWh are consumed? kWh= 480.34 So an electric water heater consumes 480.34 kWh in a year. If 1 kWh costs 11.5 cents, 480.34 kWh how many cents does it cost? cost= 5,523.91 cents Finally, if 100 cents is equal to 1 dollar, 5,523.91 cents, how many dollars are equal? cost= 55.2391$