TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a young boy wearing black and holding a skateboard on the sidewalk'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'cooked fish and green broccoli share a single white plate'. Find frequency of the letter 'c'

SOLUTION: 3

PROBLEM: Sentence: 'the attendant is straightening a bed while someone lies in it'. Find frequency of the letter 'n'

SOLUTION:
6