# Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 125)
125.
The unit digit in the product (784 x 618 x 917 x 463) is:
2
3
4
5
Explanation:
Unit digit in the given product = Unit digit in (4 x 8 x 7 x 3) = (672) = 2
Discussion:
11 comments Page 1 of 2.

Azeem said:   8 months ago
(784 x 618 x 917 x 463)=?

Simply take the unit number from every number eg:784(4 is the unit number)
4 x 8 =32.
7 x 3 =21.

And simply take these two of the unit numbers eg:32(2 is unit number).
2 x 1=2.

Sneka said:   3 years ago
Thank you for all your explanation. I understand well.

Pritha Sarkar said:   4 years ago
Thank you all for explaining the answer.

Swar said:   4 years ago
@Neelam.

To solve this problem, we should individually divide powers of the numbers by 4, then the reminder should be taken as power for the last digit of the given number.

345/4. Reminder=1.
Unit digit of 236^345=6^ (reminder) =6^1=6.
Similarly, 144/4. Rem=0.
Unit digit of 347^144=7^0=1.

Neelam said:   8 years ago
How solve 236^345 and 347^144 for find unit digit?

Rajat said:   8 years ago
Concentrate on last line multiply unit digit of respective numbers.

Narasingarao said:   9 years ago
Dear @Rama,

784*618 8*4=32 unit place is 2 then, multiply 2*917.
-------
2*917 7*2=14 unit place is 4 then, multiply 4*463.
-------
4*463 3*4=12 unit place is 2.
-------

unit digit means last digit.
for finding the unit digit,we need only last digit of each numbers.
So 784*618*917*463 = 4*8*7*3 (for finding unit place digit)
For simply, multiply one by one
4*8=32(unit digit is 2)
2*7=14(unit digit is 4)
4*3=12(unit digit is 2)