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

Q: Sentence: 'a white bathroom sink sitting next to a toilet'. Find frequency of the letter 'i'

A: 5
****
Q: Sentence: 'a cat that is standing next to an open suitcase'. Find frequency of the letter 'e'

A: 3
****
Q: Sentence: 'many, many boats docked at a large marina'. Find frequency of the letter 'a'

A:
8
****