To find the mean we add up all the numbers and then divide that number by the amount of numbers we added up.
So in this case we added up 65, 70, 75, 80, 85, 90 & 95. This gives us 560. Now we divide 560 by 7 as that is the amount of numbers we added up. This gives us 80 which means the answer is 80.
Salesman B has no cap and get commission for everything he sells so how much he could make is over A because he has a cap and C doesn’t get commission.