Which of the digits 1, 3, 5, 7 or 9 cannot be the units digit of a power of 3
2 answers
The digit 1 cannot be the units digit of a power of 3.
AAAaannndd the bot gets it wrong yet again!
3^4 = 81
Note the pattern:
3, 9, 27, 81, 243, ...
which repeats every cycle of 4 vales.
So the only possible units digits are 1,3,7,9
so 5 is out
3^4 = 81
Note the pattern:
3, 9, 27, 81, 243, ...
which repeats every cycle of 4 vales.
So the only possible units digits are 1,3,7,9
so 5 is out