TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a young woman dressed in green and black operating a remote control'. Find frequency of the letter 'r'

SOLUTION: 5

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

SOLUTION: 4

PROBLEM: Sentence: 'a person is standing in the snow with a kite'. Find frequency of the letter 'i'

SOLUTION:
5