[Q] Premise: "A snowboarder is catching air on a snowy hill while wearing protective snow gear."
Hypothesis: "A female snowboarder is doing flips on a snowy hill."
Do we know that the hypothesis entailed by the premise?
[A] A snowboarder is catching air on a snowy hill while wearing protective snow gear does not indicate that a female snowboarder is doing flips on a snowy hill.
The answer is it is not possible to tell.

[Q] Given the sentence "Construction men fixing the freeway of an underpass." is it true that "Construction men decide to go to a pub."?
[A] The pub is not located at the freeway of the underpass so the men cannot be in two places at once.
The answer is no.

[Q] Premise: "People are walking down the street in front of a white van."
Hypothesis: "A few people are walking down the street."
Do we know that the hypothesis entailed by the premise?
[A] People are walking down the street is part of the sentence people are walking down the street in front of a white van.
The answer is yes.