In this task, you need to count the number of words in a sentence that start with the given letter. Answer with numbers and not words.

Sentence: 'a man on a beach throwing a frisbee while two people walking the water'. How many words start with the letter 'a' in the sentence.
3

Sentence: 'a woman walks in the street in the rain'. How many words start with the letter 'i' in the sentence.
2

Sentence: 'a person riding their mountain bike off road'. How many words start with the letter 'r' in the sentence.

2