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

Sentence: 'a red train traveling down train tracks near a forest'. Find frequency of the letter 'f'
1

Sentence: 'a girl playing with a frisbee while people watch'. Find frequency of the letter 'e'
5

Sentence: 'a pepperoni pizza is displayed on a wooden table'. Find frequency of the letter 'p'

5