TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a dog is shown sitting on rocks by the beach'. Find frequency of the letter 'a'

SOLUTION: 2

PROBLEM: Sentence: 'a large cooked pizza on a dining table'. Find frequency of the letter 'n'

SOLUTION: 3

PROBLEM: Sentence: 'man sitting on the side of a van playing the guitar'. Find frequency of the letter 'm'

SOLUTION:
1