June 2007 LSAT Question Explanations June 2007 - Sec 1 - Ga...

June 2007 - Sec 1 - Game 3 - Setup

Video Transcript:

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So, the third game of the June 2007 LSAT states: A cruise line is scheduling 7
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week-long voyages for the ship Freedom. Each voyage will occur in exactly one of
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the first 7 weeks of the season
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weeks 1 through 7. Each voyage will be to exactly one of four destinations: Jamaica,
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Martinique, or Trinidad. Each destination will be scheduled for at
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least one of the weeks the following conditions apply to freedom scheduled.
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Alright, first place in what we already know. This is a seven-week schedule. So, we're going
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to have seven weeks. And we have four destinations that are possible in
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Guadalupe, Jamaica, Martinique, and Trinidad and we know that each of these
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will be scheduled for at least one of the weeks. So, each of these shows up at
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least once. Alright, so let's think about what that rule is telling us. Each destination
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will be scheduled for at least one of the weeks and we have four destinations but
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seven weeks which means there are three weeks that are open. So, let's think about the
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possibilities for the numerical distribution of these destinations. So, if we
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have three weeks that are open we can have one of the destinations appear four
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times and the other three appear only once. We could also have one destination
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appear three times and another twice and the other two once. And lastly we can have
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three destinations appear twice and one destination appear one time. And again
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that's coming directly from the rule. Each destination will be scheduled for
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at least one of the weeks and the fact that we have weeks one through seven.
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Alright, so now that we have a nice base let's turn our attention to the conditions that
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are gonna apply to freedoms schedule. The first condition tells Jamaica will not
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be the destination in week 4. So, we can write Jamaica is not going to be in week 4.
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The second condition tells us Trinidad will be the destination in week seven. So,
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we can add Trinidad to week seven. So, Trinidad is definitely going to be week 7
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but keep in mind it's possible that Trinidad shows up again.
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Ok. Turning our attention to the third condition. Freedom will make exactly two
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voyages to Martinique at least one voyage to Guadalupe will occur in some week between
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those two voyages. Alright, so the third rule here. What we're seeing is two voyages
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exactly 2 to Martinique. So, you notice what that does right away is it eliminates
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the 4-1-1 possibility in our numerical distribution because if Martinique is showing
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up exactly twice in the 4-1-1 one possibility there is no one showing
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exactly twice. So, that possibility has been eliminated now based on the third
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condition. Again, the condition is that there is at least one trip to Guadalupe
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inbetween the two trips to Martinique. So, we have that block.
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Now, keep in mind we cannot make certain deductions here. For example, you cannot conclude
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based on the fact that Trinidad is 7th that Martinique cannot appear 5th because again if Martinique appeared fifth
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as long as the other Martinique appears third or earlier and Guadalupe is in between
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and it's still fine. So, we can't do anything with that rule. Turning our
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attention now to the fourth condition. Guadalupe will be its destination in the
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week preceding any Voyage it makes to Jamaica. Alright, so it's really important to think carefully about
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what this rule is saying because again we know 'any' introduces sufficient so any voyage it makes to
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Jamaica
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must be preceded by a trip to Guadalupe. And we know for sure there's going to be at least
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one trip to Jamaica. Therefore we know for sure we are going to have to place this 'G' 'J'
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box at least once in our schedule. Possibly twice but notice another
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conclusion and we can me is that J can only show up max twice because if
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Jamaica were to appear 3 times we would have to have Guadalupe in every week preceding
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those which would be six destinations already
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of the seven but we also have Martinique and Trinidad remaining to place so
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that clearly would not work. So Jamaica can only appear maximum twice. And one last
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Deduction we can make from rule number four is that Jamaica cannot be first
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because of Jamaica was first we would not have a week preceding it for Guadalupe.
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And now turning our attention to the fifth and final condition: No destination will be
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scheduled for consecutive weeks. So, telling us that we can't have Guadalupe, Jamaica, Martinique,
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or Trinidad in consecutive weeks and we know since we have Trinidad in
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week 7 that we cannot see Trinidad again in week 6. And that is the set up for this
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game. The only other thing that you should be aware of is the placement
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possibilities for our Jamaica / Guadalupe block. Again, at this point only possibilities
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are 1 and 2. We could also have that appear two and three and then four and five
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and lastly 5 and 6 and keep in mind
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have J show up twice so we could actually have two of those blocks in our
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game so let's turn our attention now to the questions...