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: 'three young children playing with a ball in front of a huge bridge'. Find frequency of the letter 'e'

Answer: 5


Question: Sentence: 'a person is riding in a cart pulled by a horse'. Find frequency of the letter 'a'

Answer: 4


Question: Sentence: 'an older man is skateboarding down a slide'. Find frequency of the letter 'n'

Answer:
4