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

[EX Q]: Sentence: 'a woman walking with a child that is in a wheelchair'. Find frequency of the letter 'k'
[EX A]: 1

[EX Q]: Sentence: 'the meal is served and ready to be eaten'. Find frequency of the letter 'e'
[EX A]: 8

[EX Q]: Sentence: 'a man serving himself pizza in a wooden booth'. Find frequency of the letter 'n'
[EX A]:
4