21with Spare Parts
posted by
Twooooo
- July 07 2011 07:29:10 AM
Using ONLY 1,5,6,7, parentheses, and the basic operations, make 21. You cannot use the numbers twice.
Reply by
Marc24
- July 07 2011 08:33:46 AM
6/(1-5/7)
Reply by
budunk
- July 14 2011 09:54:37 AM
(6*7)/sqrt(5-1)
Reply by
Caprico
- July 19 2011 08:37:45 AM
budunk, you can't use sqrt, as it is not a basic operation... (I don't think it is, is it?)