<p>If n distinct planes intersect in a line, and another line l intersects one of these planes in a single point, what is the least number of these n planes that l could intersect?</p>
<p>(A) n
(B) n - 1
(C) n - 2
(D) n/2
(E) (n - 1)/2</p>
<p>Answer is choice (B). How would you arrive that?</p>
<p>Wow, I checked out this question as well when I took the test it came from (the BB). I got this one wrong and had no idea what the answer was.</p>
<p>I am not sure but I will give my best guess. The n planes intersect in a line, and the only way a line wouldn’t intersect all n of the planes is if it was parallel to one of the planes. Therefore, if line l is parallel to one of the n planes, it would not intersect the line it is parallel with. That said, the number of planes intersected would be all but the parallel plane, aka n-1.</p>
<p>I am not sure if this is true, but it seems right to me.</p>