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 of some sort near a sink of some sort'. Find frequency of the letter 'o'

SOLUTION: 7

PROBLEM: Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'

SOLUTION: 2

PROBLEM: Sentence: 'a black cat lying in an empty suitcase peers out over the edge of the suitcase'. Find frequency of the letter 't'

SOLUTION:
7