Hello,

I've got a common question about linking up a logic chain. I just re-watched the video lesson but it's not precisely the answer to my question. Any help is appreciated!

If you have:

Premise: A ---> B ----> C

-------------------------------------

Conclusion: D ---> C

Is it correct to try to make D ---> A and D ---> B (either one works, along with their contrapositives) OR would it be correct to make A ---> D and B ---> D?

My question is from PT 47 section 3, number 21. According to the video, it is the former method, but I remember doing it the other way sometimes. I got the Q right doing it in my head but it'd be great to confirm it. Thanks again