Question

The last digit of number $7^{886}$ is

• A. 9
• B. 7
• C. 3
• D. 1

Answer 1

The correct option is A 9

Units digit in $7^1$ is $7,7^2$ is $9,7^3$ is $3,7^4$ is $1,7^5$ is $7$ and so on.

Generalizing, number of the form and corresponding units digits can be written as under.

$4n\to 1$

$4n+1\to 7$

$4n+2\to 9$

$4n+3\to 3$

The number 886 is of the form $884+2$, i.e. $4n+2$ and thus the units digit would be 9.