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 persons standing outside a moving sub train'. Find frequency of the letter 'a'

Answer: 3


Question: Sentence: 'a yellow and green train on a train track in a wooded area'. Find frequency of the letter 'o'

Answer: 4


Question: Sentence: 'a bowl of something with a spoon it'. Find frequency of the letter 'i'

Answer:
3