MathDB

The Number of Lines

Source: 1997 National High School Mathematics League, Exam One, Problem 6

March 4, 2020

Problem Statement

In the space, three lines

a,b,c

that any two in them are skew lines. Then the number of lines that intersect all of

a,b,c

\text{(A)}0\qquad\text{(B)}1\qquad\text{(C)}\text{more than one, but finitely many}\qquad\text{(D)} \text{infinitely many}