Question

A train full of passengers goes through a tunnel. When the train........single person on the train. How did it happen ?A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

Answer 1

there is no single people in the train 
there are couples and no single(unmarried)people...................

Answer 2

There is a huge flock of unmarried people with married people There are single males also....