Okay, without moving away from our given constants ie food for 50+crew and survival or food for 100 for 3 days then death, there is a rational solution, it may be a little harsh but this is how any great leader will and has in the past, take to this problem.
First, Children, you save the kids because they are most important. (i have none of my own so dont try to say im biased)
Second, Young mothers (of the above children) in good health. Sorry to those who didnt bring their kids.
Third, Young women, here is your chance at salvation those of you that didnt bring their kids but remember, there are going to be young women there without kids too so like i said, chance.
Fourth, any currently active scientists, these people are contributing to society on a larger scale than anyone else.
Fifth, its simply a random lottery from this point forward. Politicians, lawyers, whatever else excluding yourself because you had to orchestrate the ordeal and in order to circumvent mutiny you have to stay.
At any time during the first 4 rounds are the 50 spots are spoken for, you cross another issue and must take only the most viable specimens, the rest will be left behind to fend for themselves.