TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'

SOLUTION: 4

PROBLEM: Sentence: 'a silver train crossing the road on tracks'. Find frequency of the letter 'r'

SOLUTION: 5

PROBLEM: Sentence: 'a picture of an open air zone that looks incredible'. Find frequency of the letter 'c'

SOLUTION:
2