In this task, you need to count the number of times the given letter appears in the given sentence.

[EX Q]: Sentence: 'a double decker transit bus parks by a blue on the side of the street in front of a brick building in the city'. Find frequency of the letter 't'
[EX A]: 9

[EX Q]: Sentence: 'a man hits a tennis ball with a racket on the court'. Find frequency of the letter 'c'
[EX A]: 2

[EX Q]: Sentence: 'a red pickup truck traveling through an intersection'. Find frequency of the letter 'h'
[EX A]:
2