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

[EX Q]: Sentence: 'a knife a cutting board some bananas and a toaster'. Find frequency of the letter 'i'
[EX A]: 2

[EX Q]: Sentence: 'a boy swinging a bat while playing baseball'. Find frequency of the letter 'h'
[EX A]: 1

[EX Q]: Sentence: 'a set of three computer monitors sitting on top of a desk'. Find frequency of the letter 'e'
[EX A]:
5