Invitational D

[Gandhiswagg17]

Are we allowed to discuss questions from Invitational D yet?

[qwerty123]

Dude... we barely took it today.

[101dalmatians]

Yeah... lets leave that for a few days later

[101dalmatians]

What up with that 3X3 matrix?

[nsguy1350]

[nsguy1350]

Reading another post, I guess we can discuss it. The 3x3 was a great surprise, since I had never seen it on a NS test before. It was not a good test for me, at least as far as speed goes (#73). I guess I'll need to work on my NS speed a bit.

[sxk1693]

I thought the NS test on the whole was normal up to that question. I was breezing through the test thinking it would be a good one when I struck matrix stupidity with 45 seconds left. I knew how to do the question afterwards, but I decided to just go back and fill in the questions I skipped. I had a vague idea on how to do the matrix, but I did not want to risk it. For once I did not miss either 1,2, or 3 so my confidence was intact and I missed 2 questions overall on the first page. The third column was tough though, but after taking so much of those accursed medium Dr. Numsen tests, it still was pretty normal.

[101dalmatians]

[Fredfredburger]

I don't think the 3X3 matrix was that bad. If you subtract the first column from the third you get 1,1,1, which is the same as the second which means your determinant is zero. He's probably just checking if kids know matrix properties.

[101dalmatians]