TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a couple of items that are on the wall'. Find frequency of the letter 'm'

SOLUTION: 1

PROBLEM: Sentence: 'a red fire hydrant opened and spilling water'. Find frequency of the letter 'd'

SOLUTION: 4

PROBLEM: Sentence: 'a person on skis is coming down a snowy hill'. Find frequency of the letter 'n'

SOLUTION:
5