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

[Q]: Sentence: 'a person working at an airport, outside of an airplane'. Find frequency of the letter 'r'
[A]: 5


[Q]: Sentence: 'the wooden kitchen has a small child's plastic table in it'. Find frequency of the letter 'n'
[A]: 3


[Q]: Sentence: 'a close up of a plate with a whole carrot'. Find frequency of the letter 'w'
[A]:
2