If 35C n + 7 = 35C 4n - 2, then all the values of n are given by?
Correct Answer: 3, 6
Explanation:
35Cn + 7 = 35C4n - 2
We know that if nCx = nCy then, Either x = y or x + y = n Case 1: x + y = n
⇒ n + 7 + 4n - 2 = 35
⇒ 5n + 5 = 35
⇒ 5n = 30
∴ n = 6 Case 2: x = y
⇒ n + 7 = 4n - 2
⇒ 4n - n = 2 + 7
⇒ 3n = 9
∴ n = 3