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)}?
2
3
5
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 2 of 13.

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.
(1)

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.

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.

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.

Revathi said:   1 decade ago
I cant understand... explain (6*4)....

Sangee said:   1 decade ago
Please tel me how you got (6*4).

Rather than your idea is superb!


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