The GATE Grind

GATE 2025 ST – Question 44

Joint Distributions · Order Statistics · 2 marks · Multiple choice

Independent X,Y₁,Y₂ have exponential rates 2,1,1 respectively. R_i is the ascending rank of Y_i among the three observations. Find E(R₁+R₂).

  1. 13/3
  2. 22/5
  3. 21/5
  4. 9/2

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (A) 13/3

Explanation

The three ranks sum to 6. The rank of X is 1+1_(Y₁<X)+1_(Y₂<X), with each comparison probability 1/(1+2)=1/3. Thus E rank X=5/3, giving E(R₁+R₂)=6−5/3=**13/3, A**.

More Order Statistics questions

All Order Statistics questions →