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 boy catching a frisbee while standing ins bunch of leaves'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'a group of people on beach with surfboards and buildings in background'. Find frequency of the letter 'u'

SOLUTION:
4