TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a close up of a plate with a whole carrot'. Find frequency of the letter 'w'

SOLUTION: 2

PROBLEM: Sentence: 'this yellow fire hydrant sits in a grass field'. Find frequency of the letter 'i'

SOLUTION: 5

PROBLEM: Sentence: 'a yellow ribbon hanging from a street sign'. Find frequency of the letter 'b'

SOLUTION:
2