An operating system coordinations of a computers operation

How do we use the sumif formula (when dealing with different formats) ?

If an appliance consumes 500 w of power and is left on for 5 hours, how much energy is used over this time period? a. 2.5 kwh b. 25 kwh c. 250 kwh d. 2500 kwh

How are we able to create photographs differently than 100 years ago? explain your answer in relation to your photograph you selected.