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

Sentence: 'the bathroom is in need of remodel'. Find frequency of the letter 'e'
5

Sentence: 'a red and white train passing a train station'. Find frequency of the letter 'a'
7

Sentence: 'a plate of eggs, bread and avocado is shown with a fork on it'. Find frequency of the letter 't'

3