In this task, you need to count the number of times the given letter appears in the given sentence.

Q: Sentence: 'a person riding a skate board on a city street'. Find frequency of the letter 'a'

A: 5
****
Q: Sentence: 'a man playing baseball on a television set'. Find frequency of the letter 'l'

A: 4
****
Q: Sentence: 'a railroad train pulling up to the train platform'. Find frequency of the letter 'o'

A:
3
****