In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'two metal benches on an empty train platform'. Find frequency of the letter 'n'

Answer: 4

Question: Sentence: 'a man holding a brown paper bag kite'. Find frequency of the letter 'b'

Answer: 2

Question: Sentence: 'a girl in a school uniform smiles at the camera'. Find frequency of the letter 'l'

Answer:
3