TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a group of people walking down a rain soaked street with umbrellas'. Find frequency of the letter 'w'

SOLUTION: 3

PROBLEM: Sentence: 'bathroom scene with a black cat going behind the door'. Find frequency of the letter 'e'

SOLUTION: 4

PROBLEM: Sentence: 'a man that is on his cell phone'. Find frequency of the letter 's'

SOLUTION:
2