QUESTION: Premise: "A boy in a pink t-shirt is riding a bike over a sand pile while two others are riding in the street."
Hypothesis: "The boy and his friends are outside."
Do we know that the hypothesis entailed by the premise?

Let's solve it slowly: Two boys who are riding in the street need not necessarily be FRIENDS with a boy who is riding a bike over a sand pile.
The answer is it is not possible to tell.


QUESTION: Given the sentence "The snowboarder is ready to jump." is it true that "The snowboarder is competing in a snowboarding competition."?

Let's solve it slowly: Ready to jump does not necessarily mean competing in a snowboarding competition.
The answer is it is not possible to tell.


QUESTION: Given the sentence "Two homeless men and a dog sitting on the sidewalk." is it true that "Two men and a dog are on the sidewalk."?

Let's solve it slowly:
On the sidewalk is the same as sitting on the sidewalk.
The answer is yes.