KGS math club/solution 11 13
The probability of a suit being distributed to the players in some way is the same as the probability of a player having some distribution of suits. E.G. The probability that spades are 7-3-2-1 is the same as the probability that south holds a 7-3-2-1 shape.
We are asked to compare the probability that my hand is x-y-0-0 in some order, with the probability that some suit is x-y-0-0 between me and my partner. For the former there are six possible shapes (x-y-0-0, x-0-y-0, x-0-0-y, 0-x-y-0, 0-x-0-y, 0-0-x-y), and for the latter there are four possible suits. So the former is 50% more probable.