The non-negative remainder when $7^{30}$ is divided by 5 is

The value of $3^{18}(mod \space 4)$ is equal to

The unit's digit of $2^{2025}$ is

$3^{16}$ (mod 4) is equal to

If $X = 11$ and $Y = 3$, then $X \mod Y = (X + aY) \mod Y$ holds

The last digit (unit digit) of $12^{25}$ is

The least non-negative remainder when $2^{101}$ is divided by 5 is: