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 1 of 13.
Hemanth said:
1 decade ago
This can be done in a simpler manner.
The unit digit of 625^x is 5.
The unit digit of 6374^y is an even number.
When multiplied, the unit digit must be 0.
The unit digit of 625^x is 5.
The unit digit of 6374^y is an even number.
When multiplied, the unit digit must be 0.
Vaibhav said:
1 decade ago
Thanks.
A.Athiban Sakthivel said:
1 decade ago
How unit digit in [(4^2)896 x 4] is equal to Unit digit in (6 x 4) = 4 ?
Supreet singh said:
1 decade ago
I too. !
But hemanth method is good.
But hemanth method is good.
Hanah said:
1 decade ago
@Hemanth I still can't understand your method.
Don said:
1 decade ago
What happend? jus can't understand. Hemanth method is good but what if it is 622^ () then wat?
Anitha said:
1 decade ago
I can't understand.
Sangee said:
1 decade ago
Please tel me how you got (6*4).
Rather than your idea is superb!
Rather than your idea is superb!
Revathi said:
1 decade ago
I cant understand... explain (6*4)....
Jhansi said:
1 decade ago
Because 4^2=16, unit digit is 6....
like that
4^4=256, unit digit is 6..
in 4^6 , unit digit is 6......
so in (4^2)896 unit digit is 6 because 896 is an even number..
Hope you all understand..
like that
4^4=256, unit digit is 6..
in 4^6 , unit digit is 6......
so in (4^2)896 unit digit is 6 because 896 is an even number..
Hope you all understand..
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