In this task, you need to count the number of times the given letter appears in the given sentence.

Sentence: 'a person on a skateboard going down a ramp'. Find frequency of the letter 'n'
4

Sentence: 'a man paddle boarding by a boat dock in a city'. Find frequency of the letter 'o'
3

Sentence: 'a dog lays on the floor while looking up friom it'. Find frequency of the letter 'e'

2