1) Suppose that |a+b| + |b+c| + |c+a| = 20. What is the maximum possible value of |a-b|?
2) Suppose that |a - b| + |b - c| + |c - d| + ... + |m-n| + |n-o| + ....+ |x - y| + |y - z| + |z - a| = 20. What is the maxim possible value of |a-n|?
Thanks in advance.
