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

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

[EX Q]: Sentence: 'a man with a skateboard that is in the street'. Find frequency of the letter 'o'
[EX A]: 1

[EX Q]: Sentence: 'a sandwich that is on a plate on a table'. Find frequency of the letter 'a'
[EX A]:
7