Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 121)
121.
What is the unit digit in the product (365 x 659 x 771)?
Answer: Option
Explanation:
Unit digit in 34 = 1 
Unit digit in (34)16 = 1
Unit digit in 365 = Unit digit in [ (34)16 x 3 ] = (1 x 3) = 3
Unit digit in 659 = 6
Unit digit in 74 Unit digit in (74)17 is 1.
Unit digit in 771 = Unit digit in [(74)17 x 73] = (1 x 3) = 3
Required digit = Unit digit in (3 x 6 x 3) = 4.
Discussion:
39 comments Page 3 of 4.
Arun Kumar Behera said:
4 years ago
Thank you @Jyoti.
Helpful explanations create value for me.
Helpful explanations create value for me.
Sachin kumar said:
9 years ago
E.g. 3^200 * 4^500?
Solution :-
3^200 * 4^500.
200/4 = 50, remainder is 0 , 3^4.
500/4 = 125, remainder is 0, 4^4.
= 3^4 * 4^4.
= 81 * 256.
= 1 * 6.
= 6 is the answer.
Solution :-
3^200 * 4^500.
200/4 = 50, remainder is 0 , 3^4.
500/4 = 125, remainder is 0, 4^4.
= 3^4 * 4^4.
= 81 * 256.
= 1 * 6.
= 6 is the answer.
Krish said:
1 decade ago
Any other easy method?
Meenakshi said:
1 decade ago
Because this is shortcut for cyclic these types of some e.g.
1, 5, 6 = 0.
4, 9 = 2.
2, 3, 7, 8 = 4.
Rule 1. When remainder is 0 and no. At unit place is even no. Answer is always 6.
Rule 2. When remainder is 0 and no. At unit place is odd and is always 1.
1, 5, 6 = 0.
4, 9 = 2.
2, 3, 7, 8 = 4.
Rule 1. When remainder is 0 and no. At unit place is even no. Answer is always 6.
Rule 2. When remainder is 0 and no. At unit place is odd and is always 1.
Charan said:
1 decade ago
(6^4)^14x6^3 = 1x6 then how come (7^4)^17x7^3 = 1x3.
Sankavi Elango said:
1 decade ago
I don't know how to calculate the unit digit can you explain?
How you will say 3^4=1? I'm get confused can you explain me?
How you will say 3^4=1? I'm get confused can you explain me?
Aparna said:
1 decade ago
I did not get the answer how can I calculate the unit number please explain me anyone.
Unz said:
1 decade ago
How 6^59=6?
VENKATESH said:
10 years ago
Unit digit in 34 = 1 unit digit in (34)16 = 1.
Unit digit in 365 = unit digit in [(34) 16 x 3 ] = (1 x 3) = 3.
Unit digit in 659 = 6.
Unit digit in 74 unit digit in (74) 17 is 1.
Unit digit in 771 = unit digit in [(74) 17 x 73] = (1 x 3) = 3.
Required digit = unit digit in (3 x 6 x 3) = 4.
How the unit digits are find? Please explain clearly.
Unit digit in 365 = unit digit in [(34) 16 x 3 ] = (1 x 3) = 3.
Unit digit in 659 = 6.
Unit digit in 74 unit digit in (74) 17 is 1.
Unit digit in 771 = unit digit in [(74) 17 x 73] = (1 x 3) = 3.
Required digit = unit digit in (3 x 6 x 3) = 4.
How the unit digits are find? Please explain clearly.
Jignesh said:
9 years ago
@Jyothi.
Thanks for your clear explanation.
Thanks for your clear explanation.
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