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

Q: Sentence: 'a doll with huge eyes and black hair with blunt bangs holds a red umbrella'. Find frequency of the letter 'e'

A: 5
****
Q: Sentence: 'a young boy bouncing a tennis ball on a tennis racquet'. Find frequency of the letter 'a'

A: 5
****
Q: Sentence: 'a large clock mounted on the side of a red wall over a fire place'. Find frequency of the letter 'r'

A:
4
****