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: 'a man standing on a surf board in the ocean'. Find frequency of the letter 'f'

SOLUTION: 1

PROBLEM: Sentence: 'a flock of two birds flying over a dirty field'. Find frequency of the letter 'o'

SOLUTION:
4