TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a large cooked pizza on a dining table'. Find frequency of the letter 'n'

SOLUTION: 3

PROBLEM: Sentence: 'this marketplace has a lot of fresh fruit and vegetables'. Find frequency of the letter 'v'

SOLUTION: 1

PROBLEM: Sentence: 'a woman writing on a navy clear wall, in a room'. Find frequency of the letter 'a'

SOLUTION:
7