instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'this yellow fire hydrant sits in a grass field'. Find frequency of the letter 'i'
answer:
5


question:
Sentence: 'a small doughnut held in a persons hand'. Find frequency of the letter 'n'
answer:
4


question:
Sentence: 'a kitchen that has the light on in the middle'. Find frequency of the letter 'a'
answer:

3