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Maths Puzzle
Unit place digit in
7^104 is ?
Read Solution (Total 3)
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- the sequence will be
7,9,3,1,7,9,3,1,7,9..........................
so 104th term will be 1 - 14 years agoHelpfull: Yes(1) No(3)
- Unit place digit in 7^104 is 1.
7^1=7
7^2=49 = 9 (mod 10)
7^4= (7^2) * (7^2)= 9*9 (mod 10)= 81 (mod 10)= 1 (mod 10)
therefore 7^104= (7^4)^26 = 1^26 (mod 10)= 1 (mod 10) - 14 years agoHelpfull: Yes(1) No(1)
- By cyclical nature of result of powers of seven, unit place digit in 7^104 will be 1.
- 14 years agoHelpfull: Yes(1) No(0)
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