28 x 1/2 x 6/7 = 12 12 numbers are relatively prime. This trick is in my new book soon to be published. ]]>

I was just wondering how you find the sum of ll numbers less than say n which are relatively prime to n. I have came across this question multiple times actually, and I do not know how to do it. Can you please give me the formula to solve it. Thanks ]]>

Thank you Anthony for taking the time out of your summer to provide these great learning opportunities.

]]>