Couldn’t decide whether to put this in the MPSIMS thread.

This is a sample math problem from one of those “Chinese students are outstripping American ones in standardized testing…” tests. It was a nifty little problem. I got the right answer but felt I spent way too long on it (4 mins ish?) than what would constitute a “good” score.

Hm that took me about ten seconds to figure out. I think though that the prowess of Asian mathematics skills are greatly exaggerated, from my own anecdotal experience.

It took me longer to load the page than to figure out the problem (aside: I really hate web pages that jump around while they’re loading). And then I had to read it over again to be sure there wasn’t some trick I was overlooking.

i think you learn circumference in primary school, so you don’t even need a teenager to solve that. anyway, is this OECD International HS test taken by American students? if not, how do they compare the rankings?

This is where I fell, except I wasn’t very sure of my answer for some reason. I was like ‘well it really seems obvious the answer is _____, but… hmmm maybe there’s something I’m missing.’

Well, I didn’t use any real math formula, but just sort of guessed using the 200 CM factor, but I would have at least mentioned the extra bit needed to keep it sealed. I might have scored the points - but most likely the only points in the entire math section for me.

The diagram shows the arc subtends a 120 degree angle. A circle is 360 degrees and 2Pi radians in angle. Therefore Pi radians is 180 degrees, Pi/3 radians is 60 degrees, and 2Pi/3 radians is 120 degrees. The arc subtends a 120 degree = 2Pi/3 radian angle. The definition of angle is radians is arc length over radius. So the angle T = S/R where S is the (unknown) arc length, R = radius = 100 cm, and angle T is 2Pi/3 radians (= 120 degrees). So the arc length (S) is RT or 2Pi/3 times 100 cm or 200 cm * Pi/3. Their answer is 100 cm * Pi/3.

Took me longer than that, but I’ve been taught to distrust diagrams in word problems. I had to convince myself that what looked like 50% was really 50%.

In my defense, I haven’t done a geometry proof in 33 years. If I’d thought to have kids to help with their homework, I’d be better at this kind of stuff.

I do agree that this wasn’t particularly difficult. When I first looked at the problem, i was expecting to have to calculate the length of a chord intersecting the circle and then I would have been sunk.

if American students are also taking the same tests, then i must have misunderstood the point in the OP’s link. i had assumed it was “the Asian students weren’t as smart as they claim, the tests were simply easy.” btw what was your factual question, pancakes3?

Based on the article, I was worried that I over-simplified the problem, but it was as simple as I thought and my intuitive answer was correct. I think it would have been more difficult without a diagram, but then it’s only difficult because of the setup.

IMO, this is something that anyone with geometry ought to be able to answer fairly easily, and likely many people with less education, as long as they know the formula for the circumference of a circle ought to be able to get it right. Frankly, considering that geometry is a required subject, if this is one of the hardest questions, it sounds like this is a fair test for a high school education.

If that’s one of the most difficult questions, I shudder to think what the easy ones are like. Possibly:

Solve for x: 1 + 1 = x

If the vast majority of high school students in America can’t solve the linked problem, then we might as well close the doors and shut off the lights on the country, since we are doomed to become a second or third rate society.