TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a couple of men sitting next to each other under an umbrella'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'three men are in a kitchen cooking and cutting through a dish'. Find frequency of the letter 'a'

SOLUTION: 4

PROBLEM: Sentence: 'a couple of street signs hanging from the side of a pole'. Find frequency of the letter 'g'

SOLUTION:
3