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 on stiltz is standing under a pink umbrella'. Find frequency of the letter 's'

SOLUTION: 3

PROBLEM: Sentence: 'a young boy holding a piece of paper on top of a table'. Find frequency of the letter 'y'

SOLUTION: 2

PROBLEM: Sentence: 'an elephant with its mouth open and some bushes and trees'. Find frequency of the letter 'd'

SOLUTION:
2