Remember, mean is average. So first you add them all up, and then divide by the total number. All the dollars added up and then divided by 6 equals 59. So, working backwards, if you multiply 6 (the number of categories) by 59 you get the total of all money earned from every category. 6 times 59 equals 354. But if you add what you can see right now, it only equals 274. So the t-shirt total must be the difference between the two... 80 dollars.
A linear pair is a pair of angles that form a straight line and are therefore, equal to 180 degrees
3n + 19 + 55 + 33 = 180
3n + 107 = 180
3n = 180 - 107
3n = 73
n = 73/3
so < EFG = 3n + 19 = 3(73/3) + 19 = 73 + 19 = 92
and < GFH = 55 + 33 = 88
10 n = C
Finding the total would simply be multiplying the cost of the tickets by number of students.
