TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a train sits on a railroad track as a metal awning covers it'. Find frequency of the letter 'l'

SOLUTION: 2

PROBLEM: Sentence: 'an old woman is holding her cat in front of a camera'. Find frequency of the letter 'r'

SOLUTION: 3

PROBLEM: Sentence: 'two professional baseball players standing on a baseball field'. Find frequency of the letter 'r'

SOLUTION:
2