TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a white toilet sitting next to a toilet paper roller'. Find frequency of the letter 'o'

SOLUTION: 4

PROBLEM: Sentence: 'a variety of a different type of vegetables'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'a man holding a baseball and a baseball glove'. Find frequency of the letter 'd'

SOLUTION:
2