TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man in a suit makes the first slice into a cake'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'a crowd of people standing in front of a green train'. Find frequency of the letter 'g'

SOLUTION: 2

PROBLEM: Sentence: 'the man is riding his bike down the busy city street'. Find frequency of the letter 'y'

SOLUTION:
2