Subcategories

• Week 1

  Ordered Arrangements, Venn Diagram, Overlapping Worlds, Careful Casework

  Day 1 Day 2 Day 3 Day 4
  39
  Topics
  127
  Posts

  E

  The way I did it, and I thought he would too, was by considering the possible placements of B for any place of A. Since after we have defined 2 of the 4 elements, the other two can only be arranged in two ways. Then, you can add up all the ways to put A before B with considering the other two elements as one singular one, and then multiply by 2.
  So, with A in front 3 placements work, second, 2 and so on, so that we get 3+2+1=6. Then, we multiply by 2 to get 12.
  this also works on the your turn, except that there is actually only 1 arrangement of C and D for every placement of b.

• Week 2

  Day 5 Day 6 Day 7 Day 8
  29
  Topics
  78
  Posts

  B

  In the video, when Prof. Loh was explaining the second way to do the pirates and gold coins problem, he only took away 8 choose 3. I thought you should take away all the different cases like 7 choose 3, 6 choose 3, etc. Why didn't he take away the rest? Thanks.

• Week 3

  Day 9 Day 10 Day 11 Day 12
  41
  Topics
  138
  Posts

  F

  Actually, never mind. I just realized that Prof. Loh just explained it in the next part.

• Week 4

  Counting Orderings, Matchings, Pouring Buckets, Polyhedra

  Day 13 Day 14 Day 15 Day 16
  20
  Topics
  55
  Posts

  F

  Screen Shot 2023-03-14 at 8.32.19 AM.png

  Hi! I don't understand why it's 6 gold pirates and not 7 if there are 7 numbers on the number line...? It's not like the separators a, b, and c will be placed between the numbers, or will they? But I do understand why it's 4 pirates. Thanks!