Traffic jams and congestions often occur in the most unlikely scenarios. And it's all our fault. We did this to ourselves. So long as we fail to follow the "Always in the Middle" rule, we have, shall and will continue to make traffic jams.

[Sec 3 Maths and Beyond: Combinatorics & Derangements] Merry Christmas to you all! Kept you waiting, huh? Have you ever played Secret Santa before? You know, randomising the gift you're giving to the other person and not knowing who's going to get what. Or so it goes, but it's not always perfect, is it? There are other ways of making the distribution consistent, of course, but there's a certain je ne sais quoi to doing it with your family and friends with everyone gathered ar