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

Q: Sentence: 'a doorway looking into a small bathroom with white toilet'. Find frequency of the letter 'r'

A: 2
****
Q: Sentence: 'a man riding on the back of a white horse next to other horses'. Find frequency of the letter 'o'

A: 6
****
Q: Sentence: 'a group of people playing wii in a living room setting'. Find frequency of the letter 'a'

A:
3
****