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

[Q]: Sentence: 'a white cat sitting on a couch in a den'. How many words contain the letter 'l' in the sentence.
[A]: 0


[Q]: Sentence: 'a man sits on a bench with a dog in lap reading'. How many words contain the letter 'x' in the sentence.
[A]: 0


[Q]: Sentence: 'a long train going down the train track'. How many words contain the letter 'i' in the sentence.
[A]:
3