@itxMaggei 22. If you enter the room with 50 people, then there’s now 51 people in it. The killer walks in and now there’s 52. He kills 30 so now there’s 22 since it’s confirmed that he didn’t walk out the room. But if we count the dead bodies still, then it’s 52.
@renabaddie_ It’s 13 yall. Remember that each son has a sister. It doesn’t mean there’s 11 girls (which is the trap the riddle want you to fall into). They all share one sister and the dad makes 13