Premise: "Many young boys and girls in a classroom leaning on each other in a line and smiling."
Hypothesis: "The young people are wearing school uniforms."
Do we know that the hypothesis entailed by the premise? Let's be accurate as possible and think first.
Many young boys and girls in a classroom leaning on each other in a line and smiling does not indicate that are wearing school uniforms. Final answer: it is not possible to tell.