The least value of n for which the number of integral terms in the Binomial expansion of is 183 , is :
- (A)2184✓ Correct
- (B)2148
- (C)2172
- (D)2196
Answer: (A)
Solution
The general term of is
For this term to be an integer, must be a multiple of (making the second exponent an integer); since is itself a multiple of , is then a multiple of precisely when is a multiple of .
The valid values of are , up to ; there are of them. Setting this to :
The least in this range that is also a multiple of is (since ).
For this term to be an integer, must be a multiple of (making the second exponent an integer); since is itself a multiple of , is then a multiple of precisely when is a multiple of .
The valid values of are , up to ; there are of them. Setting this to :
The least in this range that is also a multiple of is (since ).
JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Single correct option