3 vs 7: A Question in Ethics

One day my older brother came home with a question he was asked in class: imagine you're in a train car racing down a hill and you can't stop. Ahead of you the track forks one track (a) has 3 people tied down and the other track (b) has 7 people tied to it and the people you hit will die. You can switch the track the train takes but you can't stop the train or jump out. Which track do you take? You probably said track (a) the first option because it's better to kill 3 people than 7. That was easy but what if you knew some of the people same question but this time imagine 3 people from school who you don't really like maybe you even hate them but you know them you've seen their parents you've met there friends and know people would miss them if they died. which track would you choose the one with 7 strangers or the one with 3 acquaintances? I can't even say I know what i would do but maybe you know what you would do (tell me in the comments) But here's the big question: imagine you're in a train car racing down a hill and you can't stop. Ahead of you the track forks one track (a) has 7 people tied down and the other track (b) has 1 person but, that one person is your mother, tied to it and the people/person you hit will die. You can switch the track the train takes but you can't stop the train or jump out. Which track do you take?
  

"The truth is, hardly any of us have ethical energy enough for more than one really inflexible point of honor."
~George Bernard Shaw