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

Sentence: 'city two way street with cars lined up on both sides'. Find frequency of the letter 'h'
2

Sentence: 'an airplane is being towed away from the jet bridge'. Find frequency of the letter 's'
1

Sentence: 'a wash basin and towel rack in a washroom'. Find frequency of the letter 'w'

3