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

Sentence: 'a dog on a couch near many pillows'. Find frequency of the letter 'p'
1

Sentence: 'a picture of a machine built next to a street'. Find frequency of the letter 'x'
1

Sentence: 'a small boat in a large body of water'. Find frequency of the letter 'l'

3