TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a person standing operating a cell phone in a room'. Find frequency of the letter 'n'

SOLUTION: 6

PROBLEM: Sentence: 'a baseball player dropping his bat and starting to run'. Find frequency of the letter 'o'

SOLUTION: 2

PROBLEM: Sentence: 'a man racing a motorcycle on top of a race track'. Find frequency of the letter 'k'

SOLUTION:
1