Math, asked by tezzzz30, 1 year ago

unit's digit in the no' (12357)^655

Answers

Answered by Raghul101
25
(12357)^655

The unit digit of 12357 which is 7 determines the value of the exponent (12357)^655

Therefore we have to find the unit digit of the exponent 7^655 to find the unit digit of (12357)^655

7^1=7
7^2=49
7^3=343
7^4=2401
7^5=16,807

Therefore 7 repeats in the unit digit after every forth power of 7 and any exponent in the form 7^4n+1 ends in the unit digit 7

7^655=7^4(163)+1 × 7^2
=7×49=343
unit digit of 343 is 3

Therefore the unit digit of the exponent (12357)^655 is 3

tezzzz30: your ans is right but you have done a very long procedure for this.
Answered by pinkybansal1101
3

Answer:



Step-by-ste

p(12357)^655

The unit digit of 12357 which is 7 determines the value of the exponent (12357)^655

Therefore we have to find the unit digit of the exponent 7^655 to find the unit digit of (12357)^655

7^1=7

7^2=49

7^3=343

7^4=2401

7^5=16,807

Therefore 7 repeats in the unit digit after every forth power of 7 and any exponent in the form 7^4n+1 ends in the unit digit 7

7^655=7^4(163)+1 × 7^2

=7×49=343

unit digit of 343 is 3

Therefore the unit digit of the exponent (12357)^655 is 3

_________________

@phenom

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