TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'

SOLUTION: 3

PROBLEM: Sentence: 'oranges are sitting in a bowl on a table'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'a white toilet in a houses small bathroom'. Find frequency of the letter 'h'

SOLUTION:
3