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

Sentence: 'a birthday cake with a number one and three candle'. Find frequency of the letter 'w'
1

Sentence: 'a truck with a camper sits parked in some vegetation'. Find frequency of the letter 's'
3

Sentence: 'a man that has a racket in his hand'. Find frequency of the letter 'e'

1