instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a train station with a train pulling into the platform'. Find frequency of the letter 'i'
answer:
6


question:
Sentence: 'some people sitting on surfboards in the water'. Find frequency of the letter 't'
answer:
4


question:
Sentence: 'a train car with graphittie on it is stopped in the station'. Find frequency of the letter 'i'
answer:

8