TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a street at night with trees and streetlights on'. Find frequency of the letter 't'

SOLUTION: 9

PROBLEM: Sentence: 'person wearing all white leaned up against a wall with a yellow sign'. Find frequency of the letter 'a'

SOLUTION: 8

PROBLEM: Sentence: 'a double decker bus is driving by several other buses'. Find frequency of the letter 'a'

SOLUTION:
2