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

Sentence: 'a glass bowl of raw broccoli, a ceramic bowl of raw green chili peppers, and steel bowl of raw daikon'. Find frequency of the letter 'a'
9

Sentence: 'a man is taking a picture of a man and woman'. Find frequency of the letter 'a'
8

Sentence: 'a person is doing a trick on a skateboard'. Find frequency of the letter 'a'

5