–15FOUR STAMP DEALERS (ABBY, BAKER, CARMEN, AND DAVID) EAC...
Questions 13–15Four stamp dealers (Abby, Baker, Carmen, and David) each attend a differentday of a stamp convention, held Thursday through Sunday of one week.Carmen attends earlier than Abby.David attends later than Baker.You may want to draw a simple diagram symbolizing the information containedin the conditions. Because you know that Carmen attends earlier than Abby, youmay want to put Carmen somewhere to the left of Abby. (Note that “earlier” doesnot mean exactly one day earlier, but rather “sometime earlier”):Thurs Fri Sat Sun C ? AAnd because David attends later than Baker:B ? DNotice that although no exact days can be determined from the information, youdo know that C must be somewhere to the left of A and that B must be somewhereto the left of D. You can, if you wish, eliminate some possibilities as impossible,or rule breakers:A D B C C ? AThurs Fri Sat Sun B ? D
13.
Which of the following is a possible order of attendance at the convention?A. Carmen, David, Abby, and BakerB. Baker, Carmen, David, and AbbyC. David, Carmen, Abby, and BakerD. Abby, Baker, David, and CarmenE. Abby, Carmen, David, and BakerB is correct. To solve this problem, look for orders that are not possible or rulebreakers. You could eliminate choices D and E because they violate the first con-dition that “Carmen attends earlier than Abby.” Choices A and C violate the sec-ond condition that “David attends later than Baker.”14.
If Carmen attends the convention on Saturday, who must attend onThursday?A. AbbyB. BakerC. DavidD. Either Abby or DavidE. Either Baker or DavidB is correct. Questions that use conditional information (if, suppose, given that,assume, and so on) intend that you use that information, but only for that particu-lar question. So, for this question only, if Carmen attends on Saturday, Abby mustattend on Sunday, because the first condition states that Carmen attends earlierthan Abby. Because David attends later than Baker, of the remaining two days,Baker must attend on Thursday, and David must attend on Friday. Now that youhave used the conditional information included in that question, return to the in-formation contained only in the original conditions. (Disregard the informationadded in the preceding question.)Your diagram could have looked like this:B D C A B ? D15.
Each of the following is possible EXCEPTA. Baker attends the convention on Thursday.B. Carmen attends the convention on Thursday.C. Abby attends the convention on Sunday.D. David attends the convention on Saturday.E. Baker attends the convention on Sunday.E is correct. Again, use rule breakers to answer this question, but when you findthe rule breaker, you have the right answer. Because David attends later thanBaker, Baker cannot attend the convention on Sunday.