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 person working at an airport, outside of an airplane'. Find frequency of the letter 'r'

Answer: 5


Question: Sentence: 'a man walking a large elephant down a dirt road'. Find frequency of the letter 'g'

Answer: 2


Question: Sentence: 'a sleeping child holding a wii controller in hand'. Find frequency of the letter 'a'

Answer:
3