TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a pizza is in a box on a table outside'. Find frequency of the letter 'u'

SOLUTION: 1

PROBLEM: Sentence: 'a couple of girls are hanging out at a restaurant'. Find frequency of the letter 'l'

SOLUTION: 2

PROBLEM: Sentence: 'a big building with a tower on top with a clock on it'. Find frequency of the letter 'i'

SOLUTION:
6