Let me re-post a discussion about this question here, to keep things nice and tidy!

acc0520 wrote:Hi,

I can't understand why (E) is not right for the Q17. Because T can't be more than two in this set-up. There's no explanation about (E) in your diagram.

Can anybody explain it?

Thanks!

lucia2 wrote:I think I can help with your question. The easiest way to figure out this question is to look back at diagrams that you did in figuring out the other questions.

Why D is right:

We know we have to have two M's, and at least one G, J, and T. For each J, we must have a G right before it. So if we have 2 J's, 2 G's, and 2 M's, that's already six and forces us to make the last destination T. If we had THREE J's, that would force us to have THREE G's, and our TWO required M's, which already makes seven and we didn't even include T.

Why E is wrong:

However, if we had three T's, that is, Freedom made MORE than 2 voyages to Trinidad, then we could have the following scenarios:

From 1-7: T M G J T M T, for example

Or you could have: M T G J T M T

There are many other possibilities. It's really easiest to just try it out and see if you can.

Basically, the point in these kinds of questions are to look for the variables that have constraints on them. Example, J has a huge constraint on it because it's always attached with G. M has a constraint on it because we know there are only 2 and they are separated by at least one G.

T is the only variable without constraint--we know it has to be in the 7th spot, but that's it. For questions that are must be true/false, etc the answer tends to be variables with constraints on them, because those usually have to be one way or another (there aren't as many possibilities about where to put them).

shawtydatblade wrote:I am also questioning the difference between answers D and E. I can see why D must be true. However, since J is never at week 4, T cannot be visited more than two times within the seven day range. Am I missing something here?