hazelnut wrote:
In Wareland last year, 16 percent of licensed drivers under 21 and 11 percent of drivers ages 21-24 were in serious accidents. By contrast, only 3 percent of licensed drivers 65 and older were involved in serious accidents. These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers are.
Which of the following is an assumption on which the argument depends?
Pre-Thinking what author is saying:1.) presents some figures.
2.) Conclusion: greater experience and developed habits are the reason, why the 65+ year olds have such a low accident rate.
What did the author assume to draw that conclusion?That 65+ year olds have " greater experience and developed habits" in the first place. Only then would that conclusion make sense.
(A) Drivers 65 and older do not, on average, drive very many fewer miles per year than drivers 24 and younger.
Expl: Wordy, but hits the point. The author assumes that 65+ year olds have greater experience, therefore the assumption that 65+ year olds drive
at least as much as 24-and-younger-ones do, is pretty much what we want.
There still could be a better answer choice which says that 65+ year olds
definitely have better experience or smth.....so keep looking. But hold
A) for now.
Good choice so far!(B) Drivers 65 and older do not constitute a significantly larger percentage of licensed drivers in Wareland than drivers ages 18-24 do.
Expl: Quick look back at the figures tells us, that the figures are already in percent. So if 65+ year olds would make up a larger percentage, still only 3 percent would be involved in accidents.
Assumptions on percentages would have absolutely no effect because of that. Also, the author is saying nothing that would be attributable to a lesser/larger percentage of licensed drivers of a group.
Incorrect.(C) Drivers 65 and older are less likely than are drivers 24 and younger to drive during weather conditions that greatly increase the risk of accidents.
Expl: One may could be tempted by this answer. Because we are looking for an assumption that states that 65+ year olds have more experience.
But this answer choice here goes one step further and says that 65+ year olds definitely drive less on bad weather conditions. We cannot necessarily say that. we have to be strict.
Incorrect.(D) The difference between the accident rate of drivers under 21 and of those ages 21-24 is attributable to the greater driving experience of those in the older group.
Expl: Another more tempting answer choice. in a general term it says, the author assumes that difference in accident rate between age groups is attributable to greater driving experience.
Which sounds to be in the line of reasoning of the author. But look closely, thats all there is to it.
First, why is it so specific about the younger two groups? Could be better if it talks about two groups involving those 65+ year olds, since we are talking about them.
Secondly, and more importantly, this just restates the conclusion. Not what the author assumes. It just restates the conclusion that difference in accident rates is because of the better driving experience. GMAT never asks in Assumption-Questions for answer choices that just restate what the author is saying. Thats not an unstated assumption. those restatements can not be correct in assumption questions!!!
Incorrect.(E) There is no age bracket for which the accident rate is lower than it is for licensed drivers 65 and older.
Expl: Does the author assume that in order to draw his conclusion? Does the author assume that the accident rate is lowest for 65+ year olds in order to draw the conclusion that they have such low accident rates because of their better experience? Think about it..... No!
Incorrect.Only
A) is left, make your move then.