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

Sentence: 'a line of people on motorcycles on the road'. Find frequency of the letter 'e'
5

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

Sentence: 'people fishing and enlarge mountainlake with trees lining the shoreline'. Find frequency of the letter 't'

4