TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a bus is stopped in front of a graphic statue'. Find frequency of the letter 'e'

SOLUTION: 2

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

SOLUTION: 4

PROBLEM: Sentence: 'a man standing on top of a beach near a yellow umbrella'. Find frequency of the letter 'l'

SOLUTION:
4