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: 'a little boy that has a toothbrush in his mouth'. Find frequency of the letter 'r'

Answer: 1


Question: Sentence: 'a parking meter painted green with a sign that describes it as not a parking meter'. Find frequency of the letter 's'

Answer: 4


Question: Sentence: 'two young men in a skate park watching a third young man performing a trick on a skateboard'. Find frequency of the letter 'r'

Answer:
6