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 giraffe shares a habitat with a zebra, an ostrich, and an okapi'. Find frequency of the letter 'e'
3

Sentence: 'a bride and groom slicing into a wedding cake'. Find frequency of the letter 'i'

5