TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'a street at night with trees and streetlights on'. Find frequency of the letter 't'

SOLUTION: 9

PROBLEM: Sentence: 'a man and several white red and blue airplanes'. Find frequency of the letter 'u'

SOLUTION: 1

PROBLEM: Sentence: 'two marine air crafts with people near by'. Find frequency of the letter 'w'

SOLUTION:
2