TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a bunch of green bananas is hanging on a tree'. Find frequency of the letter 'n'

SOLUTION: 7

PROBLEM: Sentence: 'a teenager witting on a futon couch holding gaming controls in both hands'. Find frequency of the letter 'c'

SOLUTION: 3

PROBLEM: Sentence: 'a park where people in groups are enjoying.a boy is balancing on a board and playing on an air filled matress'. Find frequency of the letter 's'

SOLUTION:
4