Step-by-step explanation: First you have to find the amount of minutes in 5 hours so you do 5*60 which equals 300. Then you want to divide the total number of iPhone by the total amount of minutes (6,300/300) which gives you 21 iPhones a minute.
1) You must do division first. So divide 5/12 and get .41666666... 2) Then you add 15+5 and get 20. 3) Finally you subtract 20 and .41666666... and you get 19.5833333... 4) you can simplify 19.583333... to 19.584 if you need to.
