TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'the bathroom is in need of remodel'. Find frequency of the letter 'e'

SOLUTION: 5

PROBLEM: Sentence: 'a stop sign next to houses with christmas lights'. Find frequency of the letter 's'

SOLUTION: 7

PROBLEM: Sentence: 'a group of people watching a man give a demonstration'. Find frequency of the letter 'r'

SOLUTION:
2