In this task, you need to count the number of words in a sentence that contain the given letter

[EX Q]: Sentence: 'a bed has an empty bag and folded laundry stacked on it'. How many words contain the letter 'm' in the sentence.
[EX A]: 1

[EX Q]: Sentence: 'this is a yellow train riding the rails'. How many words contain the letter 'n' in the sentence.
[EX A]: 2

[EX Q]: Sentence: 'a marc train sits on the train tracks'. How many words contain the letter 'r' in the sentence.
[EX A]:
4