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 train sits on a railroad track as a metal awning covers it'. Find frequency of the letter 'l'

Answer: 2


Question: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'

Answer: 1


Question: Sentence: 'a pitcher throwing a ball during a baseball game'. Find frequency of the letter 'r'

Answer:
3