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: 'group of snowboarders on a snowy trail overlooking a mountain'. Find frequency of the letter 'r'

A: 5
****
Q: Sentence: 'a man riding on the back of a horse through a leaf covered forest'. Find frequency of the letter 'd'

A:
2
****