TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a bathroom that has it's lights turned on'. Find frequency of the letter 'h'

SOLUTION: 4

PROBLEM: Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'a man taking a picture of a man on a motorcycle'. Find frequency of the letter 'a'

SOLUTION:
7