It seems to me that if you remove the time constraint, the g-level is really quite low. It says "Jamaica will not be its destination in week 4.", so just go through the options and cross out all the options where Jamaica is its destination in week 4. That gets rid of D. "Trinidad will be its destination in week 7." gets rid of E. "Guadeloupe will be its destination in the week preceding any voyage it makes to Jamaica." gets rid of C. "at least one voyage to Guadeloupe will occur in some week between those two voyages." gets rid of B. That leaves A. I don't see how intelligence comes in, except insofar as it allows one to perform the task more quickly. It's not a "Can you do logical reasoning"? test, it's a "Can you follow simple instructions under time pressure?" test.