Latest TCS Aptitude Question SOLUTION: unit digit of 4^5^6^7^8^9

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(#M40026385) TCS Numerical Ability question Keep an EYE

unit digit of 4^5^6^7^8^9

Asked In TCS Kunal Verma (10 years ago)

Unsolved Read Solution (20)

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Read Solution (20) :

anamika  (10 years ago)

4.. since 5^anything wil result in no having unit digit 5(which is odd)..so as per encyclicity of 4.. unit digit will be 4.

Is this solution Helpfull? Yes (30) | No (16)  

Ayushi Singla  (10 years ago)

it should be 6...
unit place of 4^5 is 4 n then 4^6 is 6 n then 6^smthng is 6
pls correct me if m wrong

Is this solution Helpfull? Yes (28) | No (19)  

siddharth kumar  (10 years ago)

but here 4^(5*6*7*8*9)= 4^(15120) so 15120 is even ....so 4^(even)=6 at unit
am i ryt...

Is this solution Helpfull? Yes (24) | No (5)  

GAURAV JAISWAL  (10 years ago)

Answer will be 4 bcoz4. 5^anything wil result in no having unit digit 5(which is odd)..so as per cyclicity of 4.. unit digit will be 4

Is this solution Helpfull? Yes (13) | No (6)  

shiv kumar garg  (10 years ago)

write 4=2^2
now2*5*6*7*8*9=3024
2^1=unit digit is 2
2^2=.....4
2^3=...8
2^4=...6
2^5=...2
2^6=..4
nw cycle is here n=4
3024%4=0
so unit's digit is last no. of cycle
that is 6

Is this solution Helpfull? Yes (9) | No   

Deepika Jain  (10 years ago)

4^5=1024
1024^6^7^8^9
6*7*8*9=3024
we could take last two digit of 1024..i.e24
(24)^3024
last digit will be 6
as 24^even=ends in76

Is this solution Helpfull? Yes (4) | No (6)  

Ayushi Singla  (10 years ago)

@Anamika it should b considered frm base of not?
how can we assume 5^smthng wen it itself is a power?

Is this solution Helpfull? Yes (2) | No (1)  

pritam banerjee  (10 years ago)

5 to d pwer anything gives 5 as last digit...4 to d pwer 5 gives last digit as 4

Is this solution Helpfull? Yes (1) | No (4)  

Amisha Agarwal  (10 years ago)

ans:4
as 9 can be witten as 4*2 +1
so 4^1=4

Is this solution Helpfull? Yes (1) | No (3)  

pandimurugan  (10 years ago)

ans:4 ; 4^5=4

Is this solution Helpfull? Yes (1) | No (4)  

Guru Pranav  (10 years ago)

SINCE 5 TO THE POWER ANYTHING WILL BE 5,
SO, 4^5 = 1024,

4 will be the LAST DIGIT !!!

Is this solution Helpfull? Yes (1) | No (3)  

camelia saha  (10 years ago)

6 is the unit's digit!

Is this solution Helpfull? Yes (1) | No   

VISWANATH  (10 years ago)

correcr answer please

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Manuvesh Bhaskar  (10 years ago)

Correct answere is 4

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rams  (10 years ago)

result of 5^x
in units place is always 5
so 4^x
x is somedigit having 5 in its units place..
for 4 ^ something in odd we get 6 in units place...
so ans is 6

Is this solution Helpfull? Yes | No (1)  

Udaya  (9 years ago)

anything 5 power will give unit digit as 5
so 4^5
4^1=4
4^2=16
4^3=-4
4^4=--6
4^5=---4
so 4 is unit digit

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sarvesh gupta  (9 years ago)

correct ans=6..100%

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Surendra Gangisetti  (8 years ago)

4^5=1024.
6*7*8*9=3024
we could take last two digit of 1024..i.e24
(24)^3024
last digit will be 6

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janmanjay banerjee  (8 years ago)

any power of 4 gives only 2 outcomes in unit's digit i.e, 4 and 6. for odd multiple of power unit is 4 where as for even multiple unit is 6. here total power is(5*6*7*8*9)=15120 exactly divisible by 4
ANS=6

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Ishita  (7 years ago)

Answer will be 4 becoz 5 raised to any power gives last digit 5 and 4 to the odd power gives 4. Moreover for those who r getting ans 6, I'll gv an example, 2^2^3 is 2^8 and not 2^6 ie we dont multiply power for such cases, while (((2)^2)^3) will give 2^6. Also the calculation is from top to down and nt otherwise.

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