Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 10)
10.
What is the unit digit in {(6374)1793 x (625)317 x (341491)}?
Answer: Option
Explanation:
Unit digit in (6374)1793 = Unit digit in (4)1793
= Unit digit in [(42)896 x 4]
= Unit digit in (6 x 4) = 4
Unit digit in (625)317 = Unit digit in (5)317 = 5
Unit digit in (341)491 = Unit digit in (1)491 = 1
Required digit = Unit digit in (4 x 5 x 1) = 0.
Discussion:
123 comments Page 2 of 13.
Seema said:
1 decade ago
Seema:As 6374 = unit digit is 4,
in 625 = itz 5 n in 341 = itz 1
just multiply all the degit units = 4*5*1 = 20
in 20 = unit digit is 0
So, ans is 0
in 625 = itz 5 n in 341 = itz 1
just multiply all the degit units = 4*5*1 = 20
in 20 = unit digit is 0
So, ans is 0
Priyankavanga said:
1 decade ago
@Seema
I am satisfied with your answer.
Thanku very much.
I am satisfied with your answer.
Thanku very much.
Suhas said:
1 decade ago
Great discussion to understand the unit digit.
Karthi said:
1 decade ago
What is Unit digit ?
Nandish said:
1 decade ago
Thank you seema. Got it.
Venkatesh said:
1 decade ago
Find the unit digit in (264)^102 + (264)^102.
Venkatesh said:
1 decade ago
Find the unit digit in (264)^102 + (264)^103
Shahid said:
1 decade ago
The process generally is like this
Say 4^0=1 5^0=1 1^0=1 (1 time)
4^1=4 5^1=5 1^1=1 (2nd time)
4^2=16 5^2=25 1^2=1 (3rd time)
4^3=64 5^3=625 1^4=1 (4th time)
So as per problem units number must be the result of
(4^1793)*(5^317)*(1^491)
From the above calculations done it is evident that
1^anything =1 and 5^any positive number gives 5 as units digit
Similarly with 4 powers
Now take 4^1793.......First divide the power 1793/4 gives remainder 1.
So Units digit is (4^1)*5*1=20 whose
units digit is 0
Say 4^0=1 5^0=1 1^0=1 (1 time)
4^1=4 5^1=5 1^1=1 (2nd time)
4^2=16 5^2=25 1^2=1 (3rd time)
4^3=64 5^3=625 1^4=1 (4th time)
So as per problem units number must be the result of
(4^1793)*(5^317)*(1^491)
From the above calculations done it is evident that
1^anything =1 and 5^any positive number gives 5 as units digit
Similarly with 4 powers
Now take 4^1793.......First divide the power 1793/4 gives remainder 1.
So Units digit is (4^1)*5*1=20 whose
units digit is 0
Emela said:
1 decade ago
How can you divide 1793 simply by 4 and write that remainder? is it applicable for any number like 6^, 7^.
Pratiksha said:
1 decade ago
What is unit digit ?
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