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

[EX Q]: Sentence: 'a passenger train that is going over a bridge'. Find frequency of the letter 't'
[EX A]: 3

[EX Q]: Sentence: 'three young people goofing around; one of the guys has a football, the girl has a teddy bear'. Find frequency of the letter 'd'
[EX A]: 3

[EX Q]: Sentence: 'two bathroom sinks next to each other in a restroom'. Find frequency of the letter 'n'
[EX A]:
3