TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two men with colorful ties are posing for a picture'. Find frequency of the letter 'r'

SOLUTION: 4

PROBLEM: Sentence: 'a herd of horses standing next to each other on a field'. Find frequency of the letter 'r'

SOLUTION: 3

PROBLEM: Sentence: 'a man stands on a snow board in the snow'. Find frequency of the letter 't'

SOLUTION:
2