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UPSC CDS Math Number System Questions
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© examsnet.com
Question : 14
Total: 102
What is the unit place digit in the expansion of
7
73
?
[2019 CDS-I]
1
3
7
9
Validate
Solution:
We know that unit’s digit of (odd number)
4
N
=
1
Unit's digit of
7
73
Unit’s digit of
=
7
72
×
7
[72 is a multiple of 4]
= Unit’s digit of
7
72
=
1
Thus, unit digit of
7
72
×
7
=
1
×
7
=
7
© examsnet.com
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