Originally Posted by gearboxman

Ok.
Rear toothcount is 13/58
Front toothcount is 13/32
To work out the relationship we must first convert to fractions of the same total, so:
Multiply out the fractions to get 416/1856 and 754/1856 (58x32, 13x32, 13x58)
Now we have a relationship.
Add 416 and 754 together which forms our whole: 1170.
Now divide 416 by 1170 = 0.3555555555555555555555555etc
Divide 754 by 1170 = 0.64444444444444444444444etc

To achieve a 50:50 split you would need double planets, which are effectively two sets of planets in the same carrier.
One set will mesh with the annulus, with the other meshing with the sun.
Toothcounts are monkeyed with to achieve identical ratios
For example: 20/40 is the same ratio as 15/30 (2:1)