TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'

SOLUTION: 1

PROBLEM: Sentence: 'a person on a sidewalk jumping with an umbrella'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'a glazed yeast doughnut on a paper sheet'. Find frequency of the letter 'o'

SOLUTION:
2