TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a person holding onto a pink kite at the beach'. Find frequency of the letter 'n'

SOLUTION: 4

PROBLEM: Sentence: 'a white toilet sitting next to a toilet paper roller'. Find frequency of the letter 'o'

SOLUTION: 4

PROBLEM: Sentence: 'a bus and cars are on a street with a traffic light'. Find frequency of the letter 'a'

SOLUTION:
7