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

Sentence: 'a bowl of granola with raspberries and honey on top with a spoon'. Find frequency of the letter 'w'
3

Sentence: 'a tennis player after hitting a shot back to the other side of the court'. Find frequency of the letter 'n'
3

Sentence: 'a girl looks at a cell phone while at her fruit stall in the market'. Find frequency of the letter 'o'
3