TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a double parking meter is decorated with a picture of a girl with wings on her feet'. Find frequency of the letter 'r'

SOLUTION: 6

PROBLEM: Sentence: 'a person on a surfboard in the surf of a wave'. Find frequency of the letter 's'

SOLUTION: 3

PROBLEM: Sentence: 'a person holding a large green phone in a classroom'. Find frequency of the letter 'e'

SOLUTION:
5