TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'

SOLUTION: 3

PROBLEM: Sentence: 'a display case filled with lots of different clocks'. Find frequency of the letter 'w'

SOLUTION: 1

PROBLEM: Sentence: 'bushels of bananas hanging from a rope in a store'. Find frequency of the letter 'n'

SOLUTION:
5