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What is the units digit of 13^27?

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Bunuel
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What is the units digit of 13^27? [#permalink] What is the units digit of 13^27?   02 Nov 2020, 03:00
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A
B
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D
E

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What is the units digit of \(13^{27}\)?

A. 1
B. 2
C. 3
D. 7
E. 9
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D
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rajatchopra1994
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Re: What is the units digit of 13^27? [#permalink] What is the units digit of 13^27?   02 Nov 2020, 03:06
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Explanation:

13^27
Cyclicity of 3 is 4 : 3,9,7,1 ; so 3^27 will be 7

Unit digit will be 7

IMO-D
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Abhishek009
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Re: What is the units digit of 13^27? [#permalink] What is the units digit of 13^27?   02 Nov 2020, 08:21
Bunuel
What is the units digit of \(13^{27}\)?

A. 1
B. 2
C. 3
D. 7
E. 9
\(13^{6*4}*13^3\)

\(13^{6*4}\) will have units digit as 1 and, \(13^3\) will have units digit as 7

So, The units digit of \(13^{27}\) will have units digit as 7, Answer must be (D)
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Re: What is the units digit of 13^27? [#permalink] What is the units digit of 13^27?   02 Nov 2020, 08:23
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for these king of question , we just need to pay attention to unit digit

which will be same as the 3^27

since 3 has cyclicity of 4 ; we can divide 27 by 4 and get the remainder of 3 (

hence 3 rd digit in the cyclicity (3,9,7,1) will be the unit digit i.e. 7

hence D



Bunuel
What is the units digit of \(13^{27}\)?

A. 1
B. 2
C. 3
D. 7
E. 9
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Re: What is the units digit of 13^27? [#permalink] What is the units digit of 13^27?   09 Aug 2024, 05:50
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Re: What is the units digit of 13^27? [#permalink]
09 Aug 2024, 05:50
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