TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'an commercial airline airplane flies above the clouds'. Find frequency of the letter 'n'

SOLUTION: 3

PROBLEM: Sentence: 'a woman walking with a child that is in a wheelchair'. Find frequency of the letter 'k'

SOLUTION: 1

PROBLEM: Sentence: 'a man holding a tennis racquet on a court'. Find frequency of the letter 'a'

SOLUTION:
5