I need help learning how to model in blender can anybody show me the basics of modeling?

Which of the following “invisible” marks represents an inserted tab?

Ihave been given the number of guns per 100, and the total firearm-related deaths per 100,000. i have to find the actual number of guns per country and actual number of gun-related deaths. if somebody could show me how to do 1 question, i can finish the rest, i am just confused. tia

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