Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 108)
108.
What is the unit digit in (4137)754?
1
3
7
9
Answer: Option
Explanation:

Unit digit in (4137)754 = Unit digit in {[(4137)4]188 x (4137)2}

=Unit digit in { 292915317923361 x 17114769 }

= (1 x 9) = 9

Discussion:
18 comments Page 1 of 2.

Ammudhanush said:   4 years ago
4137^754,

Step 1: The unit digit of the exponent 4137 is 7,
Step 2: Divide 754 by 4 (754÷4); remainder = 2,
Step 3: From step 1 &2=> 7^2 =49.

So, the unit digit of 49 is 9.

Therefore, the answer is 9.
(8)

Maneesha said:   5 years ago
7^754 = ((7^4)^187)*7^6 | 7^4=81 here unit digit of 81 is 1)
= ((1)^187)*(7^4)*7^2.| 7^4=81 here unit digit of 81 is 1)
= 1*1*49.
= 1*49.
= 1*9(in 49, the number 9 is unit number)
= 9.
So is divisible by 9 so the answer is 9.

Reddivari radha gayathri said:   5 years ago
According to the cyclicity:

754/4 = remainder is 2.
In 4137^754 consider unit digit i.e 7^754.
replace the power with remainder i.e 7^2.
49 they asked unit digit so consider a unit digit.
Answer = 9.
(3)

Aditya Dheer said:   5 years ago
The correct answer is 1.
(1)

MD AFTAB ALAM said:   6 years ago
@Manish.

4 ka 4th power =256 not 2401.

Arvind said:   6 years ago
What will be the unit number of (3^57*6^41*7^63)?
(1)

Satpreet said:   9 years ago
If we consider (4137^2) ^377 is it right or is there compulsory to consider 4 as the power?

Krishna said:   9 years ago
The units will be like.

7^1=7.
7^2=49; unit dig=9,

For 7^3 = 343; uit dig=3.
For 7^4=___1 (unit dig =1).

Then it follows as. 7, 9, 3, 1 consecutively. Here we have cycles of 4.

Therefore, 752 can be divided from 4.
752 = 1.
753 = 7.
754 = 9; by using the cycle the answer is 9.
(4)

Mohan s said:   9 years ago
@Manish Methani. How 4 To the power 4 is 2401? Just explain.

Aditya said:   1 decade ago
Why it can't be solve like this (4137)^754?

As 7^4 as equal to 1.


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