The last digit in $7^{300}$ is

We have, $$ \begin{aligned} &7^{1}=7 \\ &7^{2}=49 \\ &7^{3}=343 \\ &7^{4}=2401 \end{aligned} $$ and so on. Thus, the last digit repeat itself in multiple of 4 . Since, 300 is divisible by 4 , the units digit of $7^{300}$ would be 1 .