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

[Q]: Sentence: 'oranges are sitting in a bowl on a table'. Find frequency of the letter 'a'
[A]: 5


[Q]: Sentence: 'a person does a trick on a ramp on a snowboard'. Find frequency of the letter 's'
[A]: 3


[Q]: Sentence: 'a couple of people on bikes ride through the street'. Find frequency of the letter 'o'
[A]:
5


