TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two elephants walking on cement next to wall'. Find frequency of the letter 'n'

SOLUTION: 5

PROBLEM: Sentence: 'a group of workers washing and cleaning fruits and vegetables'. Find frequency of the letter 'i'

SOLUTION: 3

PROBLEM: Sentence: 'a man wearing glasses cooking a chicken in the oven'. Find frequency of the letter 'e'

SOLUTION:
5