Not exactly a trolley problem but close enough
You are locked in a room with someone who wants to die but is young and has a loving family, this person likely will not change their beliefs but will never be able to commit suicide or die before their predetermined death date. Theres another person who wants to live but is old and has only 1 living family member which they are not close with, this person likely will not change their beliefs but will never be able to commit suicide or die before their predetermined death date. You have a gun and must shoot one, trying to shoot yourself will always fail and not picking anyine will kill all 3 of you. You cannot communicate to either of these people until after you choose one to kill and you are unable to ever tell them their death date. No one will know about what happened except the survivor and you and neither are able to discuss it with anyone but eachother. If you regret the decision, you cannot go back or kill the survivor and if they try to seek revenge, they always fail.