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

[EX Q]: Sentence: 'three woman are having a discussion in the kitchen'. Find frequency of the letter 'n'
[EX A]: 5

[EX Q]: Sentence: 'a man using a video game controller in a room'. Find frequency of the letter 'n'
[EX A]: 4

[EX Q]: Sentence: 'a man in a suit and hat standing next to a bicycle'. Find frequency of the letter 'a'
[EX A]:
7