8th Canadian Mathematical Olympiad Problems 1976

8th Canadian Mathematical Olympiad Problems 19761.  Given four unequal weights in geometric progression, show how to find the heaviest weight using a balance twice. 2.  The real sequence x0, x1, x2, ... is defined by x0 = 1, x1 = 2, n(n+1) xn+1 = n(n-1) xn - (n-2) xn-1. Find x0/x1 + x1x2 + ... + x50/x51.