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)?
1
2
4
6
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 4 of 4.

Ruqiya said:   9 years ago
How it comes 6 power of 59 which equals to 6.

Please explain this.
(1)

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.

Unz said:   1 decade ago
How 6^59=6?

Aparna said:   1 decade ago
I did not get the answer how can I calculate the unit number please explain me anyone.

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?

Charan said:   1 decade ago
(6^4)^14x6^3 = 1x6 then how come (7^4)^17x7^3 = 1x3.

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.

Krish said:   1 decade ago
Any other easy method?

Gjkk said:   1 decade ago
Why we take power of 7 is only 4?


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