# Online math quiz - I have questions about 1 of them **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 19, 2020, 4:17pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329 "2020-10-19T16:17:03Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 21, 2020, 2:18pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/21 "2020-10-21T14:18:48Z")
I was going to ask about this question. But realized it needed the multiple choice to choose. You do have to know the formulas. Perimeter is the sum of the sides. For a square you can use p=4S Area of a square is S^2 where S is a side. [![](https://i.dailymail.co.uk/1s/2020/10/18/16/34537756-8852665-image-m-85_1603035088370.jpg) ](https://i.dailymail.co.uk/1s/2020/10/18/16/34537756-8852665-image-m-85_1603035088370.jpg) ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [October 21, 2020, 2:36pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/22 "2020-10-21T14:36:21Z")
> [@LSLGuy](#): > > An old saw in developer land: There are 3 kinds of people: Those who can count, and those who can’t. I have a T-shirt that says “There are two kinds of people: those who can extrapolate from incomplete information.” ---
**Author:** ![slalexan](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@slalexan](https://boards.straightdope.com/u/slalexan)\ **Post date:** [October 21, 2020, 3:17pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/23 "2020-10-21T15:17:01Z")
> [@aceplace57](#): > > I was going to ask about this question. But realized it needed the multiple choice to choose. > > You do have to know the formulas. > > Perimeter is the sum of the sides. For a square you can use p=4S > > Area of a square is S^2 > where S is a side Unless I’m missing something, I don’t think you need multiple choice for this one. s=side length A=area P=perimeter A=s^2 P=4s A=P s^2=4s s^2-4s=0 s\*(s-4)=0 s=0, s=4 ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 21, 2020, 3:25pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/24 "2020-10-21T15:25:27Z")
> [@aceplace57](#): > > I was going to ask about this question. But realized it needed the multiple choice to choose. > > You do have to know the formulas. > > Perimeter is the sum of the sides. For a square you can use p=4S > > Area of a square is S^2 > where S is a side. An interesting question because it’s equating units and square units. At least they had the courtesy / good sense to include the word “value” so we know they’re just talking about the numeric result, not the physical / mathematical reality of what the results _mean_. See this thread for a mild religious war about math problems of this nature: > [@Help with a possible math discrepancy?](https://boards.straightdope.com/t/help-with-a-possible-math-discrepancy/920855): > > I am attempting to resolve an apparent mathematical discrepancy I encountered while helping one of my kids with her homework. The problem is as follows: Given a cone with a base radius r of 5 cm and a slant height (L) of 12 cm, where the surface area in square cm equals the volume in cubic cm, solve for the height (h) of the cone. The formulas are helpfully provided: Surface area = pi x r^2 + pi x rL Volume = 1/3 x h x pi x r^2 So we know we can set these two formulas as an equation: pi x… As to this problem specifically, as @slalexan says, it’s trivial and needs no multiple choice. Mechanically converting the words of the problem into an equation yields: > 4S = S^2. Solve for S. By inspection S=4. And of course zero is a degenerate answer as well. Also by inspection. Any equation involving just multiplication and exponentiation is trivially solved at zero. > [@RivkahChaya](#): > > I have a T-shirt that says “There are two kinds of people: those who can extrapolate from incomplete information.” I love it. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 21, 2020, 4:07pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/25 "2020-10-21T16:07:12Z")
> [@slalexan](#): > > Unless I’m missing something, I don’t think you need multiple choice for this one. Thanks slalexan I like your solution. I just brute forced it by trying values. It’s a lot better to setup a equation for the answer. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [October 21, 2020, 7:48pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/26 "2020-10-21T19:48:54Z")
> [@LSLGuy](#): > > An interesting question because it’s equating units and square units. At least they had the courtesy / good sense to include the word “value” so we know they’re just talking about the numeric result, not the physical / mathematical reality of what the results _mean_ . Right. So a 4ft x 4ft square would qualify, but a 48in x 48in square would not. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 21, 2020, 9:10pm UTC](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329/27 "2020-10-21T21:10:39Z")
> [@Thudlow\_Boink](#): > > Right. So a 4ft x 4ft square would qualify, but a 48in x 48in square would not. Exactly. Idjits. As was discussed in the other thread I linked. Wherein IIRC you got in a few good licks too. [Previous page](https://boards.straightdope.com/t/online-math-quiz-i-have-questions-about-1-of-them/923329.md?page=1)