Permutations & Combinations
Counting Geometric Configurations
Grade 11
Question:
<p>The number of ways of selecting an edge and a face diagonal from the edges and face diagonals of a cube such that they are skew is equal to</p>
Step-by-Step Solution
Key Concept: Count pairs of an edge and a face diagonal that are skew in a cube
<p>A cube has 12 edges and 12 face diagonals. An edge and a face diagonal are skew if they do not intersect and are not parallel. The number of such pairs is 30.</p>
Correct Answer: R