TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a woman at a table checking her cell phone'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'men are riding on motorcycles with a man riding in their carriers'. Find frequency of the letter 'r'

SOLUTION: 8

PROBLEM: Sentence: 'a store shelf filled with assorted fresh fruits'. Find frequency of the letter 'i'

SOLUTION:
3