All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers
Quickie XI (Posted on 2017-11-27) Difficulty: 1 of 5
What is the last digit in S=sum(n=1 to 99) n!

See The Solution Submitted by Ady TZIDON    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution solution Comment 2 of 2 |
The first 5 factorials are
Starting there, all the factorials end in zero, so the sum of the last digits, whose last digit is the last digit of the sum, remains 1+2+6+4 = 13.   That last digit is thus 3.

  Posted by Charlie on 2017-11-27 13:06:02
Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (0)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information