TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a golden haired dog looking out of an open window'. Find frequency of the letter 'd'

SOLUTION: 4

PROBLEM: Sentence: 'a surfer wipes out on a huge wave'. Find frequency of the letter 'a'

SOLUTION: 3

PROBLEM: Sentence: 'a man at an open air market where fruits and vegatables are being sold'. Find frequency of the letter 'e'

SOLUTION:
8