instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a surfer is in the middle of an ocean wave'. Find frequency of the letter 'i'
answer:
3

question:
Sentence: 'a few giraffes standing in a field looking around'. Find frequency of the letter 'e'
answer:
3

question:
Sentence: 'a yellow fire hydrant sitting at the top of a green hill'. Find frequency of the letter 'r'
answer:
3