A class has 10 students. In how many ways 4 students can be selected if a particular student amit is selected ‘x’ times and out of those ‘x’ times another student Rohit came ‘y’ times with Amit. By what percentage ‘x’ is more than ‘y’

(Q). A class has 10 students. In how many ways 4 students can be selected if a particular student amit is selected ‘x’ times and out of those ‘x’ times another student Rohit came ‘y’ times with Amit. By what percentage ‘x’ is more than ‘y’?
Solution:-
total students = 10

& we ae to select 4 students
x = ⁹C₃ = 84
& y = ⁸C₂ = 28
∴       

So x is 200% more than y          Answer