1983 USAMO
Problem 1
If six points are chosen sequentially at random on the circumference of a circle, what is the probability that the triangle formed by the first three is disjoint from that formed by the second three?
Problem 2
Prove that the zeros of
![\[x^5+ax^4+bx^3+cx^2+dx+e=0\]](http://latex.artofproblemsolving.com/9/0/4/9049ba78fdefb11bd3a89101dac429cad1017dce.png)
cannot all be real if 
.
