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 standing on a surf board in the ocean'. Find frequency of the letter 'f'

SOLUTION: 1

PROBLEM: Sentence: 'flower in a vase full of water sitting on a stand '. Find frequency of the letter 'l'

SOLUTION: 3

PROBLEM: Sentence: 'a drain in a floor that may be used as a toilet'. Find frequency of the letter 'a'

SOLUTION:
7