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

Sentence: 'a train sits on a railroad track as a metal awning covers it'. Find frequency of the letter 'l'
2

Sentence: 'a close up of a bird on the outside window sill'. Find frequency of the letter 'c'
1

Sentence: 'a very hair arm holds a blade next to an open medicine cabinet'. Find frequency of the letter 'l'

2