2015 · Q74
The areas of three mutually perpendicular faces of a cuboid are x, y, z. If F is the volume, then xyz is equal to
Elementary MathematicsMensuration
- AF
- BF²
- C2F
- D2F²
Explanation
This tests the cuboid volume formula. If the edges are l, b, h, the three face areas are x = lb, y = bh, z = hl. Multiplying them: xyz = (lb)(bh)(hl) = (lbh)² = V² = F². Option (a) F is the trap from forgetting that each edge appears twice in the product. Hence option (b).