TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a scene at night; a plane alone on a runway with lit-up city buildings on the horizon'. Find frequency of the letter 'w'

SOLUTION: 2

PROBLEM: Sentence: 'a young boy wearing black and holding a skateboard on the sidewalk'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'a bed with the comforter turned down and a night table with a lamp'. Find frequency of the letter 't'

SOLUTION:
7