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

Q: Sentence: 'a black cat laying down on a bed'. Find frequency of the letter 'y'

A: 1
****
Q: Sentence: 'a passenger bus that is driving down the street'. Find frequency of the letter 'r'

A: 3
****
Q: Sentence: 'a man in a white suit talking on a microphone'. Find frequency of the letter 'i'

A:
5
****