TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a grapefruit, toast, coffee and other items are on a tray'. Find frequency of the letter 't'

SOLUTION: 6

PROBLEM: Sentence: 'the large modern train is on the train track'. Find frequency of the letter 'm'

SOLUTION: 1

PROBLEM: Sentence: 'a gray airplane with metal petals on the wings takes off from an airport'. Find frequency of the letter 'i'

SOLUTION:
4