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 walking a large elephant down a dirt road'. Find frequency of the letter 'g'

SOLUTION: 2

PROBLEM: Sentence: 'a bus with two floors belonging to london country'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'two ball players giving a good luck hand smack'. Find frequency of the letter 'n'

SOLUTION:
2