Q92 / 180 · COMEDK 2023 (Memory Based) · Mathematics
If $49^n+16^n+k$ is divisible by 64 for $n \in N$, then the least negative integral value of $k$ is
- Correct answerA-1
- B-2
- C-3
- D-4
Solution
Let $P(n)=49^n+16^n+k$
For $n=1$, we get
$P(1)=49^{(1)}+16^{(1)}+k=65+k$
As $P(1)$ is divisible by 64 , we take
$k=-1$
$P(1)=65-1=64$, which is divisible by 64 .
Thus, the least negative integral value of $k$ be -1 .
Hence, the correct answer is option: 'A'.