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 bathroom with a sink, counter top, and mirror is shown'. Find frequency of the letter 'i'

Answer: 4


Question: Sentence: 'two persons standing outside a moving sub train'. Find frequency of the letter 'a'

Answer: 3


Question: Sentence: 'a bear seems to be eating something against the top of his paw'. Find frequency of the letter 'r'

Answer:
1