TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'

SOLUTION: 2

PROBLEM: Sentence: 'two young ladies that are dancing in the room together'. Find frequency of the letter 'a'

SOLUTION: 4

PROBLEM: Sentence: 'there are many dishes in the sink and magnets on the refrigerator'. Find frequency of the letter 'n'

SOLUTION:
6