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

Sentence: 'a double-decker bus covered in children's illustrations driving next to a van'. Find frequency of the letter 'a'
4

Sentence: 'a group of people standing around a table filled with assorted electronic devices'. Find frequency of the letter 'w'
1

Sentence: 'cows have lined up close together near a wooden fence'. Find frequency of the letter 'w'

2