TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a sheep in a field in front of other sheep'. Find frequency of the letter 'f'

SOLUTION: 3

PROBLEM: Sentence: 'a man sitting on a motorcycle near two other men'. Find frequency of the letter 'r'

SOLUTION: 3

PROBLEM: Sentence: 'three dogs of different colors laying on top of the sofa'. Find frequency of the letter 'r'

SOLUTION:
3