OK, so since the twins are 2 babies
and triplets are 3 babies
and quadruplets are 4 babies
then the chance you get a quadruplet baby is higher than their relative
birth occurence, because they're double the babies!!
right?
so in fact, to get the chance of a triplet baby, you divide the number of
triplets*3 (three babies for every triplet) with
(twins x 2
+triplets x 3
+quadruplets x 4
+quintuplets x5)'
there is only 85 quintuplets, but they introduce 425 babies
so you have to multiply the 85 quintuplets with 5
