QUESTION: Premise: "Two young girls with sponge bats being to play while an older girl is acting as the referee."
Hypothesis: "The girls are playing with bats."
Do we know that the hypothesis entailed by the premise?

Let's solve it slowly: Young girls are an age group of girls. Sponge bats are often used to play with.
The answer is yes.

QUESTION: Given the sentence "Group of gymnast look on as a girl in a red bodysuit completes a stunt." is it true that "Many gymnasts watch as a competitor in a red uniform finishes her performance."?

Let's solve it slowly: Many gymnasts could be described as a group. Watch and look are the same action. A stunt and a performance are sometimes the same.
The answer is yes.

QUESTION: Premise: "Two people riding an elephant through a river."
Hypothesis: "People riding a donkey."
Do we know that the hypothesis entailed by the premise?

Let's solve it slowly:
Two people are riding an elephant through a river or riding a donkey.
The answer is no.