let B be the total number of Faey births over a unspecified periodTwins weren’t all that uncommon in Faey biology, in fact they were about 27% of all births,
with identical twins representing nearly 11% of all births, leaving 16% of twin births fraternal.
and T the total number of Faey twins born over the same period
then I is the number of Identical Faey twins
and F the number of Fraternal twins
then we can state that
a) 27% of B = T or B *0.27 = T
b) 11% of B = I or B * 0.11 = I
c) 16% of T = F or T* 0.16 = F
and naturally all twins are either fraternal or identical, afaik there is no third option, so
d) I + F = T
we can substitue d) in a), b) and c) , giving us :
a) B * 0.27 = I + F
b) B * 0.11 = I
c) (I+F) * 0.16 = F
or
a) B * 0.27 = I + F
b) B * 0.11 = I
c) I * 0.16 = F - 0.16F <=> 0.16I = 0.84F
multiplying both sides with 100 to make for integers products :
a) 27 B = 100 I + 100 F
b) 11 B = 100 I <=> B = 100I / 11
c) 16 I = 84F <=> F= 16I / 84
substituting b) and c) in a) gives
a) 27 * 100 I / 11 = 100 I + 100 * 16 I / 84
or
a) I * 2700 /11 - I * 100 - I * 1600/84 = 0
or
a) I * (2700/11 - 100 - 1600/84 ) = 0
or
a) I * (126.4069 ) = 0
this can only be true for I = 0
so substituting I=0 in the original statements ,gives values of B = 0 , F = 0 , T = 0
so no Faey are born at all, and so no Faey can exist