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

Q: Sentence: 'a man riding a white surfboard on a large wave'. Find frequency of the letter 'a'

A: 7
****
Q: Sentence: 'a picture of two men on a motorcycle in front of a railroad track'. Find frequency of the letter 'n'

A: 4
****
Q: Sentence: 'a piece of film shows two street signs crossing each other'. Find frequency of the letter 'f'

A:
2
****