TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'man in a sleeping bag on the floor using a laptop computer'. Find frequency of the letter 'i'

SOLUTION: 3

PROBLEM: Sentence: 'a dilapidated bench in a park under a tree'. Find frequency of the letter 'p'

SOLUTION: 2

PROBLEM: Sentence: 'group of surfing equipment sitting next to a beach'. Find frequency of the letter 'o'

SOLUTION:
3