In this task, you need to count the number of times the given letter appears in the given sentence.
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Question: Sentence: 'three woman are having a discussion in the kitchen'. Find frequency of the letter 'n'

Answer: 5

Question: Sentence: 'small black bird with red on its head standing on a tree branch'. Find frequency of the letter 'b'

Answer: 3

Question: Sentence: 'a couple of buses parked on the side of the street'. Find frequency of the letter 'b'

Answer:
1