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

[EX Q]: Sentence: 'a black computer with a screen reading "press any key to begin."'. Find frequency of the letter 'a'
[EX A]: 5

[EX Q]: Sentence: 'a bunch of fruit sitting in a bowl, its overflowing'. Find frequency of the letter 't'
[EX A]: 4

[EX Q]: Sentence: 'a cake and the different stages of it being served and eaten'. Find frequency of the letter 'a'
[EX A]:
6