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

Sentence: 'many different species of sheep in display at a museum'. Find frequency of the letter 'h'
1

Sentence: 'the snowboarder wearing a dark helmet sprays snow into the air'. Find frequency of the letter 'w'
3

Sentence: 'a bunch of school buses that are parked in a big lot'. Find frequency of the letter 'a'
5