TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a yellow and green train on a train track in a wooded area'. Find frequency of the letter 'o'

SOLUTION: 4

PROBLEM: Sentence: 'a desk covered in notepads, a laptop and other devices'. Find frequency of the letter 'c'

SOLUTION: 2

PROBLEM: Sentence: 'traffic and pedestrian signals mounted below wires and poles'. Find frequency of the letter 'f'

SOLUTION:
2