I seem to have totally hijacked this, so what's the harm with another Nemesis story:
We took CS201 (discrete math) together. One test was exactly one problem long and scheduled for a 90 minute class period. The core insight was that it decomposed into "Take the product of all f(N) together for N = 1 through N = 25", where f(N) was something looking vaguely algebra 2-y. Hand calculation looked like it would take, oh, north of an hour.
On inspection of f(N), I noticed that it contained the term "(BLAH BLAH BLAH BLAH BLAH) * (.5N - 11) / (BLAH BLAH BLAH)". This obvious makes f(22) 0, thus making simplifying the expression or calculating f(1..21) and f(23..25) then multiplying rather moot.
Now, our professor was not a very tricksy guy, so I figured "Hah, betcha didn't see f(22) coming now did you" was not exactly his style, so I went back to check my assumptions. But they were, unquestionably, right.
So I went up approximately 4 minutes into the exam and said "Umm, sir, I'm done." He looked surprised. I said "If you're surprised, then I think there's a bug in the problem." He said I had probably made an arithmetic mistake and I would hate to lose all credit for the test.
Back to seat. Checked setup of expression. Nope, sorry, it was absolutely mathematically unavoidable that (.5N - 11) was in there.
So I went back to the prof, now 5:15 into the 90 minute long test, and said "Sir, I really think I'm right here. I'll take the zero if I botched this -- can you take a look for me right now?" So he looks it over for 20 seconds, smiles, says "That is what I get for having grad students write my exams" (this quote is literally accurate), and takes my exam.
I had a friend in the class with whom I was going to go to a study group after the test was over. Not having anything else to do, I waited for him.
Twenty minutes later, Nemesis exits the class -- "first" to finish the test, naturally. Without prompting, he says "Don't feel bad, not everyone can hack discrete math. No reason to waste time on the exam if you're not going to get the right answer." "Ahh, out of idle curiosity, what did you get?" "It's complicated but..." biggest smile of my college career
We took CS201 (discrete math) together. One test was exactly one problem long and scheduled for a 90 minute class period. The core insight was that it decomposed into "Take the product of all f(N) together for N = 1 through N = 25", where f(N) was something looking vaguely algebra 2-y. Hand calculation looked like it would take, oh, north of an hour.
On inspection of f(N), I noticed that it contained the term "(BLAH BLAH BLAH BLAH BLAH) * (.5N - 11) / (BLAH BLAH BLAH)". This obvious makes f(22) 0, thus making simplifying the expression or calculating f(1..21) and f(23..25) then multiplying rather moot.
Now, our professor was not a very tricksy guy, so I figured "Hah, betcha didn't see f(22) coming now did you" was not exactly his style, so I went back to check my assumptions. But they were, unquestionably, right.
So I went up approximately 4 minutes into the exam and said "Umm, sir, I'm done." He looked surprised. I said "If you're surprised, then I think there's a bug in the problem." He said I had probably made an arithmetic mistake and I would hate to lose all credit for the test.
Back to seat. Checked setup of expression. Nope, sorry, it was absolutely mathematically unavoidable that (.5N - 11) was in there.
So I went back to the prof, now 5:15 into the 90 minute long test, and said "Sir, I really think I'm right here. I'll take the zero if I botched this -- can you take a look for me right now?" So he looks it over for 20 seconds, smiles, says "That is what I get for having grad students write my exams" (this quote is literally accurate), and takes my exam.
I had a friend in the class with whom I was going to go to a study group after the test was over. Not having anything else to do, I waited for him.
Twenty minutes later, Nemesis exits the class -- "first" to finish the test, naturally. Without prompting, he says "Don't feel bad, not everyone can hack discrete math. No reason to waste time on the exam if you're not going to get the right answer." "Ahh, out of idle curiosity, what did you get?" "It's complicated but..." biggest smile of my college career