SAT Math question

This SAT Math Question Got No Correct Submissions. Can You Solve It? 

 

 

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Answer To Everyone Got This SAT Math Question Wrong. Can You Solve It?

There’s a reason no one selected the right answer: the answer choices were all wrong!
Here’s what the test preparers had intended.

Since the circle A has 1/3 the radius of circle B, its circumference is also 1/3, and so it would revolve around the circle B 3 times. So they intended to have the correct choice as 3 times, answer choice b.
This answer would be true IF the small circle was rolling in a straight line. But let’s actually try it. You can watch the video starting around 55 seconds to see the difference between rolling on a straight line versus rolling around a circle.

If we roll around circle B, there are1, 2, 3, and 4 revolutions!


So the correct answer is 4.
The 4 revolutions are due to: 3 revolutions due to distance–since circle A has 1/3 the radius–and 1 revolution since the center of circle A revolves around the center of circle B.
In general, a circle that has 1/n times the radius will roll around similarly in n + 1 trips.


Since all the answer choices were wrong, logically no student could select the correct answer. One student did protest that the choices were wrong, and the test makers did admit their mistake.
Also, is it just me, or was the SAT a lot harder in 1982?