I have a positive integer 'n'>100. I take n! ,then I sum the all its digits, a number comes, then I again sum it's digit. I do it till I get a single digit . What is the single digit?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
It's answer is 9 for all values of n greater than 6. The n! Will be multiple of 9, so it's digit sum will also be multiple of 9. If digit sum is multiple of 9, then it's digit sum will also be multiple of 9, I do it again and again, in end I will get it as 9.