SOLUTION: The tens digit of 2^100 is: (a)4 (b) 5 (c) 6 (d) 7 (e) None of the above

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Question 290231: The tens digit of 2^100 is:
(a)4 (b) 5 (c) 6 (d) 7 (e) None of the above
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
THE POWERS OF 2 ARE:
2
4
8
16
----
32
64
128
256
----
NOTE THE REPEAT SEQUENCE OF THE UNITS DIGIT.
EVERY FOURTH POWER ENDS IN THE DIGIT 6.
THUS THE 1,000 POWER WILL ALSO END IN A 6.
ANS. C)