Discrete math Definition and 206 Threads

Suppose 2n people sit on a round table and are shaking hands in pairs. Suppose that etiquette is observed and no 2 shakes cross. Let S_n be the number of possible shaking hands arrangements of this sort. Determine S_10.

Suppose 2n people sit on a round table and are shaking hands in pairs. Suppose that etiquette is observed and no 2 shakes cross. Let S_n be the number of possible shaking hands arrangements of this sort. Determine S_10.

Hexadecimal numbers are made using the sixteen digits 0 - 9, A-F. how many hexadecimal numbers are there between the hexadecimal numbers 30 and AF? There are 8 numbers between 3 and A, so I got 3 x 16, but I don't really know.

A Discrete Math textbook first proved that the statement: 0 < x < 1 -> x^2 < 1 is true (I have no problem following the proof). It then went to prove the contrapositive: x^2 >= 1 -> x <= 0 or x >= 1 Here's the proof: Assume x^2 >= 1. (no problem here) If x <= 0, we...

Hi, Does there exist a function f: Z+ --> Z which is onto? I had been told there such funciton exists, since both Z+ and Z are countable infinite series. Thus there exists some transformation that could map Z+ to every single Z However, I still can't shake off the idea that since Z+ is...

Hello, I am currently taking a course which has exercises/questions whose solutions are based on discrete mathematics. For anyone interested, the link to the course is: http://www.math.uAlberta.ca/~tlewis/222_03f/222_03f.html We are encouraged to discuss these problems with others...