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

Sentence: 'a woman swinging a tennis racquet towards a tennis ball'. Find frequency of the letter 'e'
3

Sentence: 'a batter, catcher and umpire waiting for the pitch and a major league baseball game'. Find frequency of the letter 'c'
3

Sentence: 'a close up view of a very pretty clock'. Find frequency of the letter 'l'

2