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 red and white train passing a train station'. Find frequency of the letter 'a'

Answer: 7


Question: Sentence: 'a herd of horses standing next to each other on a field'. Find frequency of the letter 'r'

Answer: 3


Question: Sentence: 'a truck brakes in the street as a group of elephants walk ahead'. Find frequency of the letter 'g'

Answer:
1