TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a black cat laying down on a bed'. Find frequency of the letter 'y'

SOLUTION: 1

PROBLEM: Sentence: 'two men sitting quietly on a park bench'. Find frequency of the letter 'a'

SOLUTION: 2

PROBLEM: Sentence: 'a cart of beans with people looking at them'. Find frequency of the letter 'r'

SOLUTION:
1