Question
Mathematics Question on distance between two points
If nC4, nC5 and nC6 are in A.P., then n is
A
(A) 7 or 14
B
(B) 7
C
(C) 14
D
(D) 14 or 21
Answer
(A) 7 or 14
Explanation
Solution
Explanation:
pC4,zC5,n C6 are in AP2⋅nC5=nC4+2C625(n−5)=1(n−4)+130by solving n=14 or 7