Mechanical Engineering Exam  >  Mechanical Engineering Questions  >   Trains arrive at a yard every 15 minutes and... Start Learning for Free
Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________
  • a)
    0.020
  • b)
    0.030
Correct answer is between ' 0.020, 0.030'. Can you explain this answer?
Verified Answer
Trains arrive at a yard every 15 minutes and the service time is 5 mi...
Given data,
Probability that there are ‘n’ trains in a system is
ρn (1 − ρ)
for 3 train in a system =
= 0.024
View all questions of this test
Most Upvoted Answer
Trains arrive at a yard every 15 minutes and the service time is 5 mi...
Solution:

Given data:

Inter-arrival time = 15 min

Service time = 5 min

To find: Probability of having 3 trains in the system

Assumptions made:

- The arrival of trains follows a Poisson distribution
- The service times follow an exponential distribution

Calculation:

1. Finding average number of arrivals in a minute

Average number of arrivals in a minute (λ) = 1/15

2. Finding average number of departures in a minute

Average number of departures in a minute (μ) = 1/5

3. Finding utilization factor (ρ)

Utilization factor (ρ) = λ/μ

ρ = (1/15)/(1/5)

ρ = 1/3

4. Finding probability of having 0, 1, 2, and 3 trains in the system

Probability of having 0 trains in the system:

P0 = 1 - ρ = 1 - 1/3 = 2/3

Probability of having 1 train in the system:

P1 = ρ(1 - ρ) = (1/3)(2/3) = 2/9

Probability of having 2 trains in the system:

P2 = ρ^2(1 - ρ/2) = (1/9)(2/3) = 2/27

Probability of having 3 trains in the system:

P3 = ρ^3/3!(1 - ρ/3) = (1/27)(3/4) = 1/36

5. Finding the required probability

The required probability is the probability of having 3 trains in the system, which is P3 = 1/36

Therefore, the probability that the yard has 3 trains in the system is 0.028 or 0.03 (approx.)

Answer: b) 0.030
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
Explore Courses for Mechanical Engineering exam

Similar Mechanical Engineering Doubts

Top Courses for Mechanical Engineering

Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer?
Question Description
Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer?.
Solutions for Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering. Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer?, a detailed solution for Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? has been provided alongside types of Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Trains arrive at a yard every 15 minutes and the service time is 5 minutes. The probability that the yard has 3 trains in the system is __________a) 0.020b) 0.030Correct answer is between ' 0.020, 0.030'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
Explore Courses for Mechanical Engineering exam

Top Courses for Mechanical Engineering

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev