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

Sentence: 'man in air skateboarding on street with building'. Find frequency of the letter 't'
4

Sentence: 'a man makes some cock tales at a desk'. Find frequency of the letter 'k'
3

Sentence: 'a cat laying next to tape and a pile of papers'. Find frequency of the letter 'c'

1