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What is the unit’s digit in the number got from the following operation: (23)10
3
9
7
1
8
Read Solution (Total 11)
-
- unit digit 3 has cyclicity 4
10/4=remainder is 2
hence 3^2=9 - 7 years agoHelpfull: Yes(13) No(0)
- first its not ankith its ankit...............apply the process of unit digit finding as it is 23^10.
now break it in the power of ((23)^4)^2 *23^2
[ (..3)*(..3)*(..3)*(..3)]^2 *[(..3)*(..3)]
[(..9)*(..9)]^2 *[..9]
[(..81)^2]*(..9)
(..1)^2 *(..9)
(...1) *(..9)=9
answer is 9
you can verify by using 23^10 on calculator - 7 years agoHelpfull: Yes(7) No(0)
- cyclicity of 3 is 4. when we divide 10 by 4, it is 2. 3^2 is 9. So, ans is 9
- 7 years agoHelpfull: Yes(2) No(0)
- 9
coz 3^0=1, 3^1=3, and this goes on and we get 3^10 as 9(in the unit digit) - 7 years agoHelpfull: Yes(1) No(0)
- Ans:-3
The last digit in lower value - 7 years agoHelpfull: Yes(0) No(3)
- 9 will be the answer
- 7 years agoHelpfull: Yes(0) No(0)
- hi ankith can u explain how it is 9
- 7 years agoHelpfull: Yes(0) No(0)
- 10÷4=remainder =2 now 3^2=9 hence unit digit is 9
- 7 years agoHelpfull: Yes(0) No(0)
- We want to find the unit digit of 23 power 10
Now
consider 3 in 23
3*1=3is the unit digit in the same way
3*3=9
9*3=7
7*3=1
1*3=3(again 3 unit digit repeated)
so for power 4 we get 3 as unit digit
They have asked power 10
so, 10-8=2
so power 2 gives 9 as the unit digit - 7 years agoHelpfull: Yes(0) No(0)
- check whether the power value is fourth multiple.... 10 is not a 4th multiple..so take 4th multiple closest to 10.. 8 is a 4th multiple..reminder is 2. then 23^8 * 23^2 . for the power 4th multiple ...if the number is odd number , ans is 1 (is the number's power is 4th multiple). and we know that 9 is a unit digit for 23^2 .. so
23^8 *23^2= > (1)*(9) = 9 is an answer (unit dig)
another examples -
1) 13^36 = 1 ( 36 is multiple of 4 so 1 is a unit dig if the no is odd , 6 is a unit dig if a no is even )
2) 56^19 = 56^16 * 56 ^2 = (6) * (6) = 6 - 6 years agoHelpfull: Yes(0) No(2)
- 3^10 =59049 unitdigit is 9
- 6 years agoHelpfull: Yes(0) No(0)
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