Miguel is moving and wants to estimate what his electricity bill will be in his new apartment. He looks at old bills and sees that he uses around 700 kWh of electricity each month. The utility company charges $6 each month plus 6.726 cents per kWh for the first 500 kWh and 8.136 cents per kWh for any kilowatt-hours above 500.
a) How much will Miguel pay for 700 kWh of electricity? People often make a common error in situations like this. The purpose of the next two questions is to help you recognize this error and correct your work in part (a) if necessary.
$
b) If someone bought three items for $1.50, 37 cents and 5 cents, how much did they spend?
$
c)Which of the following is most likely the common error in part (b)?
- Leaving off the decimal: 1.50 + 37 + 5 = $4,350
- Making an addition error such as 37 + 5 = 45 cents
- Forgetting to change the cents to dollars: 1.50 + 37 + 5 = $43.50
