Question

If $n$ is an even number, then the digit in the units place of $2^{2n}+1$ will be

• A. $5$
• B. $7$
• C. $6$
• D. $1$

Answer 1

Answer: (B)

$7$

Since $2^{2n}$ is even therefore $2^{2n}+1$ is odd,
therefore digit at unit place should be odd, rejecting option 3.
Put n = 2, we get $2^{2n}+1$ = 17,

hence digit should be 7