TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'older man getting ready to swing his bat at a ball on a stand in front of a group of viewers'. Find frequency of the letter 'n'

SOLUTION: 7

PROBLEM: Sentence: 'a black cat laying down on a bed'. Find frequency of the letter 'y'

SOLUTION: 1

PROBLEM: Sentence: 'a number of sheep in a field with dogs'. Find frequency of the letter 'a'

SOLUTION:
2