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

Q: Sentence: 'a train station with a train pulling into the platform'. Find frequency of the letter 'i'

A: 6
****
Q: Sentence: 'a doorway looking into a small bathroom with white toilet'. Find frequency of the letter 'r'

A: 2
****
Q: Sentence: 'a surfer runs along the beach with a white board'. Find frequency of the letter 'i'

A:
2
****