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 5 of 13.
Abc 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.
How?
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.
How?
Sasi said:
1 decade ago
When finally mutilpled (4*5*1) we get 20. Consider the 20, the last digit ill be the unit digit. So the answer is 0,
Got it.
Got it.
Prabagaran said:
1 decade ago
No. How to separate this sequence [(42)896 x 4].
Dibakara nayajk said:
1 decade ago
4* 4 = 16 - 6 ->2
16 *4 = 84 - 4 ->3
5 * n = ..5
1 8 n = 1
(6 /4 ) * 5 * 1 = ......0
so ans is 0;
16 *4 = 84 - 4 ->3
5 * n = ..5
1 8 n = 1
(6 /4 ) * 5 * 1 = ......0
so ans is 0;
Deepi said:
1 decade ago
Thanks to seema and jhansi.
Abhishek said:
1 decade ago
Hemant method is very good..
Thx
Thx
Ramya said:
1 decade ago
Its so simple,
Unit digit of 6374 is 4
Unit digit of 625 is 5
Unit digit of 341 is 1
Just multiply 4*5*1=20
So unit digit of 20 is 0
Answer is 0.
Unit digit of 6374 is 4
Unit digit of 625 is 5
Unit digit of 341 is 1
Just multiply 4*5*1=20
So unit digit of 20 is 0
Answer is 0.
Dr R Vasudevan said:
1 decade ago
For a number ending in 4 ( like 6534) any odd power will have unit digit 4 and Even power unit digit 6 ( 1731 is odd and hence 6534 6 1731 will have unit digit 4.
For a number ending in 5 ( like 625 ) any odd or even power , unit digit will result in 5
For a number ending in 1 ( like 341 ) any odd or even power , unit digit will result in 1
4*5*1 = 20 - Unit digit 0.
For a number ending in 5 ( like 625 ) any odd or even power , unit digit will result in 5
For a number ending in 1 ( like 341 ) any odd or even power , unit digit will result in 1
4*5*1 = 20 - Unit digit 0.
Kishore said:
1 decade ago
For finding total result is there any logic? could you please explain?
Ananya said:
1 decade ago
If the unit digit of (x-1)^2 is 5 and (x+1)^2 is 9 then determine the units of x^2?
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