instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a person on a skateboard going down a ramp'. Find frequency of the letter 'n'
answer:
4


question:
Sentence: 'a couple of men sitting next to each other under an umbrella'. Find frequency of the letter 'n'
answer:
5


question:
Sentence: 'two small dogs on the grass next to a driveway'. Find frequency of the letter 't'
answer:

4