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

[EX Q]: Sentence: 'this is a close up view of a tennis player during the game'. Find frequency of the letter 't'
[EX A]: 3

[EX Q]: Sentence: 'a person is water skiing and there are birds flying around above them'. Find frequency of the letter 'n'
[EX A]: 5

[EX Q]: Sentence: 'a woman on the beach holding a bike and her umbrella'. Find frequency of the letter 'b'
[EX A]:
3