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

Q: Sentence: 'a train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'

A: 3
****
Q: Sentence: 'a sailboat is floating near the rocky shore of a beach'. Find frequency of the letter 'o'

A: 5
****
Q: Sentence: 'a man holding a tennis racquet in a defensive stance'. Find frequency of the letter 'a'

A:
6
****