Modification : zeros

[smart_coder]

How many zeros are there at the end of 100!?

[psuresh1982]

I think the answer is 24.
Because you see at the end of the 5!(120) you got one zero. End of 10!(3628800) you got 2 zeros. if you calculate like this every 5 factorial and 10 factorial contailns a extra zero..

So now totally 20. After that one more conditions occurring here. Numbers 25, 50 and 75 when multiplied by some of the small numbers vailable eg (4, 2 and 6)generate an extra zero.

So totally 24 zeros...i don't this is the easiest way...if anyone have other simple solution then plz post here..

----------------
suresh

[smart_coder]

ur answer is correct...but i have mechanical method by which u can tell no of zeros after any number's factorial

[Barbie]

i think its 21.

[Manojks]

Hey Smart Coder

100/5 = 20
20/5 =4
4/5 = 0

20+4 = 24 zeroes....

Thanks
Manoj