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

Q: Sentence: 'baseball player reaching back as he's about to throw the ball'. Find frequency of the letter 'e'

A: 5
****
Q: Sentence: 'a white toilet sitting next to a bathroom sink'. Find frequency of the letter 'b'

A: 1
****
Q: Sentence: 'a train engine carrying carts into a station past some graffiti walls'. Find frequency of the letter 'r'

A:
5
****