TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a knife a cutting board some bananas and a toaster'. Find frequency of the letter 'i'

SOLUTION: 2

PROBLEM: Sentence: 'a line of people on motorcycles on the road'. Find frequency of the letter 'e'

SOLUTION: 5

PROBLEM: Sentence: 'a bear stuff toys hanged in a pattern'. Find frequency of the letter 's'

SOLUTION:
2