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

[Q]: Sentence: 'a cooked pizza on a silver platter with another in the background'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'a green bus driving in a street filled with heavy traffic'. Find frequency of the letter 'v'
[A]: 2


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