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Question #41805

Difficulty: 8/10 | 🟢 Free

The Question

The probability P(t)P(t) that a quantum system remains in its initial state at time t≥0t \ge 0 satisfies the differential equation dPdt=−P22tP+1\frac{dP}{dt} = -\frac{P^2}{2tP + 1} with the initial condition P(0)=1P(0) = 1. A researcher measures the state at t=2t=2 and correctly determines the probability P(2)P(2). To predict the probability at t=12t=12, the researcher incorrectly assumes the system's decay is memoryless, satisfying P(t1+t2)=P(t1)P(t2)P(t_1 + t_2) = P(t_1)P(t_2) for all t1,t2≥0t_1, t_2 \ge 0. Let PestP_{est} be the researcher's estimated probability at t=12t=12, and PtrueP_{true} be the actual probability at t=12t=12 governed by the differential equation. Find the value of PtruePest\frac{P_{true}}{P_{est}}.

Options

  • A.

    8

  • B.

    16

  • C.

    32

  • D.

    64

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Monster

Ultra-high difficulty questions designed to test your limit, stamina, and deep conceptual understanding.

Concepts Behind This Question

Independent vs Disjoint Events|Exact Differential Recognition|Implicit Differentiation Rate

Why This Question Is Tricky

Common Mistakes

This question tests the ability to recognize an ODE that is linear in the inverse derivative (tt as a function of PP) and contrasts it with the functional equation of a memoryless (independent) probability process.

The core trap lies in the conceptual bottleneck of assuming constant decay rates (Markovian independence over time segments) for a system whose transition probability rate is explicitly time-dependent.

Students who fail to invert the differential equation will be unable to find the true state probability, while those who misunderstand the memoryless property will incorrectly calculate the estimated probability.

Quick Facts About This Question

Question Information

SubjectMathematics
ChapterProbability - Class 12
ConceptIndependent vs Disjoint Events
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree