The SAT Question Everyone Got Wrong

in 1982 there was one sat question that every single student got wrong here it is in the figure above the radius of circle a is 1/3 the radius of Circle B starting from the position shown in the figure Circle A rolls around Circle B at the end of how many Revolutions of circle a will the center of the circle first reach its starting point is it a three Hales B B 3 C 6 D 9 Hales or E 9 sat questions are designed to be quick this exam gave students 30 minutes to solve 25 problems so about a minute each so feel free to pause the video here and try to solve it what is your answer I'll tell you right now that option b or three is not correct when I first saw this problem my intuitive answer was B because the circumference of a circle is just 2 pi r and since the radius of Circle B is 3 times the radius of circle a the circumference of circle B must also be three times the circumference of circle a so logically it should take three full rotations of circle a to roll around Circle B So my answer was three this is wrong but so our answers a c d and e the reason no one got question 17 correct is that the test writers themselves got it wrong they also thought the answer was three so the actual correct answer was not listed as an option on the test mistakes like this aren't supposed to happen on the SAT for decades it was the one exam every student had to take to go to college in the US it had a reputation for determining ing people's entire Futures as a newspaper from the time stated if you mess up on your sat tests you can forget it your life as a productive citizen is over hang it up son of 300,000 test takers just three students wrote about the error to the College Board the company that administers the SAT Shivan cartha Bruce to and Doug young rice I did a lot of math problems when I was young for the competitions I probably did thousands of mouth problems I read it and I was amazed how badly it's worded I just put three down I figured that's what they wanted ...