On the fifth power
Number Theory
Level
1
\[\begin{align} {\color{red}1}^5 &= {\color{red}1} \\ {\color{red}2}^5 &= 3{\color{red}2} \\ {\color{red}3}^5 &= 24{\color{red}3} \\ {\color{red}4}^5 &= 102{\color{red}4} \\ \end{align}\]
Is it true that the last digit of a whole number and that of its fifth power are always the same (in base 10)?
by
David Ingerman