City High School must put together a debating team consisting of four debaters.There are candidates of equal ability : X,Y and Z who are all seniors; and A,B,C and D who are all juniors..The school requires that there should be two seniors and two juniors in the team.It is also necessary that all of the debaters be able to work with one another. *Debaters Y and A cannot work together. *Debaters Z and C cannot work together. *Debaters A and B cannot work together. If debater A is in the team, which other debaters must be in the ream as well?

প্রশ্নমতে, A থাকবে। সুতরাং Y অবশ্যই বাদ যাবে। তাহলে Senior Member হিসেবে X ও Z কে must থাকতে হবে। অপর দিকে A থাকলে junior হিসেবে B অযোগ্য। সুতরাং junior হিসেবে D অথবা C কে নিতে হবে। কিন্তু Z অবশ্যই C - er কাজ করবে না। সুতরাং D - ই হবে 2nd Junior এক্ষেত্রে Combination হলো X, Z, and D.