guerrero25
It’s a well-known fact that a person in a state of alcoholic or drug intoxication is more likely to cause a fire than a sober person. It also seems true that an inebriated person is less capable of extinguishing fires than a sober one. Nevertheless, last year’s statistics from the Cartesian Fire Department show that more fires were caused by sober persons than by those who were inebriated.
Which of the following, if true, best explains the discrepancy above?
(A)The number of Cartesians who neither drink nor use drugs is significantly greater than the number of those who do.
(B)Many fires occur because of malfunctioning electrical and gas equipment, and most people cannot prevent those fires regardless of whether they are drunk or sober.
(C)Cartesian legislation permits drug and alcohol consumption to all Cartesians who are of full legal age.
(D)Many persons who neither drink nor use drugs, smoke cigarettes.
(E)Sometimes, it is hard to establish whether a fire was caused by someone who was sober or drunk.
Definitely A, this is a classic GMAT statistical error.
Whenever you see a question that quotes statistics, you should automatically distrust the statistics. 99.44% of the time, the flaw is right there, and it's generally around one of three subjects: % vs #, generalization or causality. In this case, the poblem revolves around the number of fires started, which obviously will be skewed towards the bigger part of the population. If half the Cartesians were constantly drunk (let's call them quadrants 2 and 4) and half the Cartesians were always sobert (quadrants 1 and 3) then it would be a discrepency that more fires are caused by sober people. However, if the vast majority of people were sober, then even if inebriated people were twice as likely to start a fire, the overall numbers would still favor sober fire starters.
B plays upon causality but offers nothing to reconcile the issue of why more were started by sober people.
E introduces an element of doubt that does nothing to reconcile the paradox at hand.
C and D are pretty clearly out of scope. They are true but irrelevant to the question.
Hope this helps!
-Ron