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 3 of 13.
Arpitha M said:
7 years ago
In short method,
6374^1793.
1793/4=448, remainder 01.
So answer is 4^1(take the last digit in 6374).
In 625^325.
325/4=79remainder 01.
So answer is 5^1.
In 341^491.
491/4=122remainder 3.
So 1^3.
Finally;
4^1*5^1*1^3=20.
In 20, take last digit 0 is the answer.
6374^1793.
1793/4=448, remainder 01.
So answer is 4^1(take the last digit in 6374).
In 625^325.
325/4=79remainder 01.
So answer is 5^1.
In 341^491.
491/4=122remainder 3.
So 1^3.
Finally;
4^1*5^1*1^3=20.
In 20, take last digit 0 is the answer.
Kanishk said:
5 years ago
Actually, in case of 4^n.
if n=odd then unit digit is 4.
If n=even then the unit digit is 6.
This alternative pattern is true for all integers after 5. Digits before 5 also have a pattern put each integer has a different pattern.
if n=odd then unit digit is 4.
If n=even then the unit digit is 6.
This alternative pattern is true for all integers after 5. Digits before 5 also have a pattern put each integer has a different pattern.
(1)
Shubham said:
1 decade ago
Hi I have few questions.
1) In the above problem we have taken the unit digits of every number regardless of of the power.
2) If any such type questions come can we use the same method to solve the problem. Please answer.
1) In the above problem we have taken the unit digits of every number regardless of of the power.
2) If any such type questions come can we use the same method to solve the problem. Please answer.
Vinay said:
1 decade ago
I have for the given problem.
4*5*1= 20 that is unit digit =0;
But for (264)^102*(264)^103 we need to get answer as 4*4 = 16 unit digit as 6,
But in test book they given answer as 0,
How it is please explain me?
4*5*1= 20 that is unit digit =0;
But for (264)^102*(264)^103 we need to get answer as 4*4 = 16 unit digit as 6,
But in test book they given answer as 0,
How it is please explain me?
Vishal Kishor Ramteke said:
5 years ago
Look here unit digit means the last digit.
Here we have - 6374*625*341=?
So, just see the last digit i.e 4,5,1 hence multiply them 4*5*1=20 now see the last digit i.e 0.
Therefore the answer is 0.
Here we have - 6374*625*341=?
So, just see the last digit i.e 4,5,1 hence multiply them 4*5*1=20 now see the last digit i.e 0.
Therefore the answer is 0.
(5)
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..
Sandeep said:
6 years ago
The easiest way is in 1793 we take last two digits and 4 divide by means 93÷4 the remainder is 1 so in 6374 the unit digit is 4 so 4^1 is 4.
The answer is 4*5*1=20 unit digit is 0.
The answer is 4*5*1=20 unit digit is 0.
Vasundhara .G said:
1 decade ago
how can you make XI (11) as nine (9) just using a single line using only once
you must not replace or erase any line ...just draw a line any where to make it give nine
you must not replace or erase any line ...just draw a line any where to make it give nine
Nil said:
1 decade ago
@Satchi Mishra.
You are wrong. Not applicable to few no.s like 2^9.
2^9 = 512. unit digit 2.
By your method:
9/5=1, remainder 4.
2^4= 16. unit digit 6.
Not matches the case.
You are wrong. Not applicable to few no.s like 2^9.
2^9 = 512. unit digit 2.
By your method:
9/5=1, remainder 4.
2^4= 16. unit digit 6.
Not matches the case.
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
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