Using correct pronouns

Each of the children willingly did (his or her, their) share of the camp duties.

Would the correct pronoun be his or her?

Someone has left (her or his, their) automobile across the highway.

Would the correct pronoun be their?

Each of children willingly did (his or her, their) share of the camp duties.

Would the correct pronoun be their?

1 answer

The first is correct. The other two are wrong. Note that the antecedent in each sentence is singular.