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Oct
11
comment Am I just not smart enough?
If the scores are up to 100, and the average is 105, it must be some weighted average, right? Can't be the arithmetic mean - which usually is the average (So wouldn't be better calling it a 'grade', or something, then?)
Oct
10
comment Am I just not smart enough?
So, 105/100 in pre-algebra? («pre-algebra in which I got a 105 average»)
Oct
8
comment Am I just not smart enough?
I can understand the point, yet the details are mostly incomprehensible for non-US(?) readers. "a 36 average" of what, what is the maximum? 200? Again "4.0 GPA", GPA? and is 4.0 good or bad?
Jun
10
comment Highest average value when rolling dices
How do you join two successive sets of 4 dice? That is, if in a second set of 4 dice (5th to 8th roll) you get the same sequence as in your example (5x1, 5x1, x2, x4; totalling 400) what is the current score? You add both sets and get 800 (400+400) Or you keep on adding and multiplying totalling 3600? (400+50=450; 450x2=900; 900x4=3600)
Apr
26
comment How can I write the numbers 5 and 7 as some sequence of operations on three 9s?
Not everybody is using Windows... (and probably even needs a specific version of it)
Apr
25
awarded  Commentator
Apr
25
comment How can I write the numbers 5 and 7 as some sequence of operations on three 9s?
excellent!! :-)
Apr
5
comment Visually stunning math concepts which are easy to explain
To me, it is quite confusing. I doubt I would learn much from this. Beautiful, yes, but the best in here?!
Mar
28
comment Can a piece of A4 paper be folded so that it's thick enough to reach the moon?
-1: interesting reply, but to some other question.
Dec
14
comment hours minutes and seconds hand will make equilateral triangle
Yes, it is not guaranteed. I said, there will be "for some sets of time and lengths"
Nov
23
comment hours minutes and seconds hand will make equilateral triangle
+1 I did it Lubin's way, but this is way nicer, with the change of coordinates. A couple of notes. If one considers a point to be a "degenerate triangle" then there would be a solution at 0h00m00s (but I wouldn't say so). If the hands are not equal then there will be solutions, for some sets of time and lengths - I checked with Maxima but the general solution seems to be a set of very large equations.
Nov
16
answered Why can't you square both sides of an equation?
Oct
2
awarded  Informed
Sep
12
answered Interesting math-facts that are visually attractive
Sep
8
awarded  Yearling
Jul
14
awarded  Critic
Jun
23
comment Why is $ \lim_{n \to \infty} \left(\frac{n-1}{n+1} \right)^{2n+4} = \frac{1}{e^4}$
The wrongness in your approach is in assuming that you can freely replace $ \lim_{n \to \infty} \left(\frac{1}{n}\right)$ by 0 (exactly zero). Loosely speaking: $ 1/n $ becomes "nearly" zero, so $ 1-1/n $ becomes "nearly" one, yet that "very small" difference may be relevant after "infinitely" many multiplications. A reference case (the reference case) being the limit shown by Inceptio in another comment
Jun
18
comment How to teach mathematical induction?
+1 for showing (at least trying to) how and why the induction step appears, instead of postulating it and then moving on to convince the class that it works.
Jun
9
revised Why don't we include $\pm\infty$ in $\mathbb R$?
remove a extra word
Jun
9
answered Why don't we include $\pm\infty$ in $\mathbb R$?