Quick Question about Math : Diagrams

[masterchiefo]

Homework Statement

A system , which comprises three components (A , B and C ) , the system fails if the first component ( A) has failed or if the other two fail simultaneously. It will be assumed that all components operate independently.

Question: Choose from the following diagrams that best fits this description :
http://i.imgur.com/JRFGFkS.png

Homework Equations

The Attempt at a Solution

My answer:
http://i.imgur.com/B6Op3ym.png

Just want to make sure I'm correct.

Thanks.

 

[PeroK]

That's not how I would interpret those diagrams. What's your thinking?

 

[Ray Vickson]

Homework Statement

A system , which comprises three components (A , B and C ) , the system fails if the first component ( A) has failed or if the other two fail simultaneously. It will be assumed that all components operate independently.

Question: Choose from the following diagrams that best fits this description :
http://i.imgur.com/JRFGFkS.png

Homework Equations

The Attempt at a Solution

My answer:
http://i.imgur.com/B6Op3ym.png

Just want to make sure I'm correct.

Thanks.

You should refer to the conventions used in your course notes and/or textbook. The "usual" interpretation of such diagrams is that when the component is operational a signal (or whatever) gets through that branch successfully. You seem to be using the opposite convention in which you look at "failure" rather than "success", but as I said, you should double-check the conventions used in your course. Depending on the interpretation, the answers will be completely different.

 

[masterchiefo]

Edit: looking at my note books.

 

[masterchiefo]

You should refer to the conventions used in your course notes and/or textbook. The "usual" interpretation of such diagrams is that when the component is operational a signal (or whatever) gets through that branch successfully. You seem to be using the opposite convention in which you look at "failure" rather than "success", but as I said, you should double-check the conventions used in your course. Depending on the interpretation, the answers will be completely different.

That's not how I would interpret those diagrams. What's your thinking?

I was interpreting it wrong:

Here is the correct answer:
http://i.imgur.com/ynKj6x7.png

do you guys agree?

 

[PeroK]

I don't think "or" is the key word. I think the key words are system and failure. You first need to define what it means for your system to fail.

In the diagram you chose, describe the state of the system as it is. And then describe the state of the system if A has failed.

What is the system doing?

 

[PeroK]

I was interpreting it wrong:

Here is the correct answer:
http://i.imgur.com/ynKj6x7.png

do you guys agree?

Yes. Think of an IT system with A, B and C as front-end components. When is your system down?

 

[Ray Vickson]

I was interpreting it wrong:

Here is the correct answer:
http://i.imgur.com/ynKj6x7.png

do you guys agree?

I do, yes (assuming that "component works" = "signal gets through").