TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'a railroad train pulling up to the train platform'. Find frequency of the letter 'o'

SOLUTION: 3

PROBLEM: Sentence: 'a motorcycle on a mechanic stand in an outside area'. Find frequency of the letter 'n'

SOLUTION:
5