TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'apples, pears, and oranges are piled up for sale'. Find frequency of the letter 'a'

SOLUTION: 6

PROBLEM: Sentence: 'two baseball players high five each other during a game'. Find frequency of the letter 'y'

SOLUTION: 1

PROBLEM: Sentence: 'a close up view of a very pretty clock'. Find frequency of the letter 'l'

SOLUTION:
2