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

[EX Q]: Sentence: 'a person dressed all in black snowboarding down a slope'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'a metallic stove top oven inside of a wooden kitchen'. Find frequency of the letter 'v'
[EX A]: 2

[EX Q]: Sentence: 'the young fellow with the tennis racket returns the volley'. Find frequency of the letter 't'
[EX A]:
7