TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'several zebras  and a giraffe in an enclosure'. Find frequency of the letter 's'

SOLUTION: 3

PROBLEM: Sentence: 'a number of small boats on a beach near an umbrella'. Find frequency of the letter 's'

SOLUTION: 2

PROBLEM: Sentence: 'boat sailing past a building with a large clock'. Find frequency of the letter 'a'

SOLUTION:
6