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 that is on his cell phone'. Find frequency of the letter 's'

SOLUTION: 2

PROBLEM: Sentence: 'a group of people standing around a table filled with assorted electronic devices'. Find frequency of the letter 'w'

SOLUTION: 1

PROBLEM: Sentence: 'there are three horses grazing on the grassy field'. Find frequency of the letter 'o'

SOLUTION:
2