IIT JEE , AIEEE Forum - Mathematics , Algebra

jatinpreet

please solve this question-

Find the no. of 0's that occur in the end of 100! .

pathfinder

Hi

If you factorize 100! then number of zeros will occur when there is one (2 x 5 ) action is happening.
Now obviously in the factors of 100! powers of 5 will be much less then powers of 2.

so the number of zeros in 100! is :

powers of 5 + powers of ( 5 x 5) + powers of ( 5 x 5 x 5) + .... and so on

powers of 5                         = 100 / 5   = 20
powers of ( 5 x 5)                 = 20 / 5 = 4
powers of ( 5 x 5 x 5)            = 0 (as 4 is less then 5)

so the number of zeros are 24.

Cheers

jatinpreet

oh yes, we just find no. of 5 and we get no.of zeros.
thanks!!

Please give me suggestions on algebra as it seems to be my weakest topic in my preperation.

Moderator

Dear Jatinpeet,
Please post your second question as a separate query.

Thanks,
Moderator
GoIIT Team

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