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

[Q]: Sentence: 'a woman is playing an interactive video game'. Find frequency of the letter 't'
[A]: 2


[Q]: Sentence: 'a bus with two floors belonging to london country'. Find frequency of the letter 't'
[A]: 4


[Q]: Sentence: 'people work on their computers while a supervisor watches'. Find frequency of the letter 'w'
[A]:
3