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 riding a white surfboard on a large wave'. Find frequency of the letter 'a'

SOLUTION: 7

PROBLEM: Sentence: 'there are two men sitting on a couch playing video games'. Find frequency of the letter 'v'

SOLUTION: 1

PROBLEM: Sentence: 'two men are outside and playing soccer with each other'. Find frequency of the letter 'c'

SOLUTION:
3