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

Q: Sentence: 'a white toilet sitting next to a bathroom sink'. Find frequency of the letter 'b'

A: 1
****
Q: Sentence: 'a close up of a train on a track in the dark'. Find frequency of the letter 'a'

A: 6
****
Q: Sentence: 'baseball batter took a swing at the ball'. Find frequency of the letter 'w'

A:
1
****