TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'slices of orange are arranged on a plate'. Find frequency of the letter 's'

SOLUTION: 2

PROBLEM: Sentence: 'two zebras feed on a plant through some wire mesh'. Find frequency of the letter 'o'

SOLUTION: 4

PROBLEM: Sentence: 'a small clack cat sitting in  a white bathtub'. Find frequency of the letter 'c'

SOLUTION:
3