Latest Infosys Aptitude Question SOLUTION: 99! how many zero's?

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(#M40157472) INFOSYS Numerical Ability question Infy qstn Keep an EYE

99! how many zero's?

Asked In Infosys kalyanamsrija (8 years ago)

Unsolved Read Solution (8)

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keerthana  (8 years ago)

99!=99/5=19
=19/5=3
so 99! has (19+3=22 zeroes)

Is this solution Helpfull? Yes (28) | No (3)  

ananya  (8 years ago)

The answer is 22.
We get 0 from 90,80, 70,60,40,30,20,10=8
now as 50 when multiplied by even no gives two zero. so now the sum is equal to 10
now 95, 85, 65,55,45,35,15,5=8 gives zero when multiplied by even no
now 75, 25 can gives 2 zero each when multplied by even no(4)= 4
so the sum is 8+2+8+4=22

Is this solution Helpfull? Yes (12) | No   

Kapish Garg  (8 years ago)

no. of zero's means check what are the total no. of factors of 2 and 5 when no. is divided by both....consider lowest no. of factors
i.e. 99/2=49,,,,49/2=24,,,,24/2=12,,,,12/2=6,,,,6/2=3,,,3/2=1.....therefore total no. of factors of 2=49+24+12+6+3+1=95
now 99/5=19,,,19/5=3.....therefore total no. of factors =19+3=22
now take lowest one....so 22 no. of zero's in 99!

Is this solution Helpfull? Yes (9) | No   

sakshi gupta  (8 years ago)

21
(99/5)+(99/25)

Is this solution Helpfull? Yes (3) | No (5)  

Akash Jain  (6 years ago)

Here is a simple trick to calculate number of zero's
The number's of 5= (99/5+99/25)taking the only quotient= 19+3=22

Is this solution Helpfull? Yes (3) | No   

Sanjeev Kumar  (8 years ago)

To find the num of zeros we need to find num of fives first.
Then num of zeros is 99/5^1 + 99/5^2 + 99/5^3 =19+3+0=22

Is this solution Helpfull? Yes (2) | No (3)  

anthony cambrit  (8 years ago)

Ans=95
as only the first 4 factorial haven't the zero in unit value

Is this solution Helpfull? Yes | No (12)  

pragya agrawal  (7 years ago)

29 is right

Is this solution Helpfull? Yes | No (4)  

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