TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'salad and vegetables with me on top of plate'. Find frequency of the letter 'o'

SOLUTION: 3

PROBLEM: Sentence: 'two people and two children walking in a building'. Find frequency of the letter 'd'

SOLUTION: 3

PROBLEM: Sentence: 'a woman writing on a navy clear wall, in a room'. Find frequency of the letter 'a'

SOLUTION:
7