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 sitting inside a green military truck talking to someone'. Find frequency of the letter 'i'

SOLUTION: 7

PROBLEM: Sentence: 'a dog is shown sitting on rocks by the beach'. Find frequency of the letter 'a'

SOLUTION: 2

PROBLEM: Sentence: 'the group of motorcyclist are parked on the side of the road'. Find frequency of the letter 'o'

SOLUTION:
7