TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a parking meter painted green with a sign that describes it as not a parking meter'. Find frequency of the letter 's'

SOLUTION: 4

PROBLEM: Sentence: 'a glass vase sits between two statues'. Find frequency of the letter 'o'

SOLUTION: 1

PROBLEM: Sentence: 'the young girl is kicking a red ball on the ground'. Find frequency of the letter 'r'

SOLUTION:
3