TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a little boy sitting on a bed in a bedroom'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'a pizza pie sitting on a wooden table with tongs'. Find frequency of the letter 't'

SOLUTION: 5

PROBLEM: Sentence: 'a child sitting on a rocking chair nice clothes on'. Find frequency of the letter 'i'

SOLUTION:
6