If the fractional part of the number is , then k is equal to:
- (A)6
- (B)8✓ Correct
- (C)4
- (D)14
Answer: (B)
Solution
Write . Expanding by the binomial theorem gives plus a sum of terms each divisible by , so for an integer . Then , whose fractional part is . Hence .
JEE Main · 2019 · 09 Jan 2019 · Shift 1 · Single correct option