TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'men standing in the grass with a frisbee'. Find frequency of the letter 'a'

SOLUTION: 3

PROBLEM: Sentence: 'a variety of a different type of vegetables'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'a bunch of sheep that are standing in a field'. Find frequency of the letter 'b'

SOLUTION:
1