TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'vanity sitting atop a base with two doors and a mirror overhead'. Find frequency of the letter 'n'

SOLUTION: 3

PROBLEM: Sentence: 'a picture of two computers on a table'. Find frequency of the letter 'r'

SOLUTION: 2

PROBLEM: Sentence: 'a man sitting in a chair reading in front of the ocean'. Find frequency of the letter 'a'

SOLUTION:
6