TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a toilet filled with a brown liner and dirty water'. Find frequency of the letter 't'

SOLUTION: 5

PROBLEM: Sentence: 'a flock of sheep grazing in a park'. Find frequency of the letter 'f'

SOLUTION: 2

PROBLEM: Sentence: 'a sheep standing in a grassy meadow with the sun on the horizon'. Find frequency of the letter 'o'

SOLUTION:
4