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 hitting a tennis ball with a tennis racquet'. Find frequency of the letter 't'

SOLUTION: 6

PROBLEM: Sentence: 'a person riding a surfboard in the middle of a wave'. Find frequency of the letter 'o'

SOLUTION: 3

PROBLEM: Sentence: 'a couple of people lying in a bed holding laptops'. Find frequency of the letter 'p'

SOLUTION:
5