Answer: a) 
b) 
c) 
Step-by-step explanation:
Given : Number of students : 11
Number of faculty members : 13
Total persons : 
Total number of ways to structure a jury of six people from a group of 24 people :-

a) Number of ways of selecting a jury of all students :-

Then , the probability of selecting a jury of all students :-

b) Number of ways of selecting a jury of all faculty :-

Then , the probability of selecting a jury of all students :-

c) Number of ways of selecting a jury of two students and four faculty :-

Then , the probability of selecting a jury of all students :-

Step-by-step explanation:
Recall the Ratio for tan
Tan(theta) = opposite / adjacent
Tan (x) = 9 / 5
solve for x (use Tan^-1(...) )