Start Learning Free

Before You Begin

Question #41702

Difficulty: 8/10 | 🟢 Free

The Question

Let RR be the region in 3D space consisting of all points P(x,y,z)P(x,y,z) that satisfy the following conditions:

  1. PP lies in the octant x≤0x \le 0, y≤0y \le 0, z≥0z \ge 0.
  2. The distance of PP from each of the coordinate planes is at most 2.
  3. The distance of PP from the plane x+2y+2z+1=0x + 2y + 2z + 1 = 0 is at most 1.

If the volume of the region RR is VV, find the value of 3V3V.

Options

  • A.

    20

  • B.

    22

  • C.

    23

  • D.

    24

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Bridge

Practice problems that bridge the gap between foundational theory and advanced practical application.

Concepts Behind This Question

Word Problem Modeling|Distance from point to plane|Octant Sign Convention

Why This Question Is Tricky

Common Mistakes

This question tests the 'Octant Sign Convention' and the dual-bound nature of the distance formula.

A common lethal mistake is defaulting to the first octant (x,y,z≥0x,y,z \ge 0), which yields a completely different constraint and a volume of 1/3.

Another high-frequency trap is dropping the absolute value in the distance inequality (solving d≤1d \le 1 instead of ∣d∣≤1|d| \le 1).

This causes the student to miss the lower bound constraint, subtracting only one tetrahedron and arriving at the trap answer of 23.

Proper algebraic substitution for the specific octant is required to correctly partition the feasible region.

Quick Facts About This Question

Question Information

SubjectMathematics
ChapterLinear Programming - Class 12
ConceptWord Problem Modeling
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree