TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man opening up a package sitting on a couch'. Find frequency of the letter 'n'

SOLUTION: 5

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

SOLUTION: 5

PROBLEM: Sentence: 'cupcakes and various fruits in dishes on a table'. Find frequency of the letter 'a'

SOLUTION:
5