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: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'

Answer: 4

Question: Sentence: 'a bird outside standing on a table looking up'. Find frequency of the letter 'b'

Answer: 2

Question: Sentence: 'a person standing next to a public transit bus'. Find frequency of the letter 'p'

Answer:
2