In this task, you need to count the occurrences of the given word in the given sentence.

Sentence: 'two females and one is throwing a yellow frisbee and the other a red one'. Count the occurrences of the word 'yellow' in the given sentence.
1

Sentence: 'a train going over a bridge that is over water'. Count the occurrences of the word 'a' in the given sentence.
2

Sentence: 'a young man riding a motorcycle having a good time'. Count the occurrences of the word 'a' in the given sentence.

3