It is C. George - Desmond is Desmond's score. And after you get their scores, you add them up to find the total.
In order to do mean you have to add all of the numbers in the list together. then divide them by the total amount of numbers (ex. 7,9,3,2,5. you would add all of these up 7+9+3+2+5=26 then you would divide that by 5 because there are five numbers in the list.
30 x 28= 840
It's would beat 840 times in half an hour.
2-3k because the difference between something means it is subtraction and the product of 3 and k would just be 3k since you don't know what k is.