instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a person trying to flip a skateboard in a garage'. Find frequency of the letter 'a'
answer:
7


question:
Sentence: 'a man flying through the air on top of a skateboard'. Find frequency of the letter 'r'
answer:
3


question:
Sentence: 'a man on snow skis going down a hill'. Find frequency of the letter 'i'
answer:

3