JonShukhrat wrote:
Dear IanStewart
I seem to be missing something important in choice B. Could you please check whether I am applying variance test correctly?
I don't see how one could evaluate the answer choices here, since the question doesn't make sense to begin with. For one thing, I don't see how one can know what the phrase "there has been no increase in the amount of money set aside by the general public in savings accounts" means. There are two perfectly reasonable interpretations:
- the total amount of money in savings accounts didn't change from last year to this year
If that's the intended meaning, then as evidence, it is useless. We'd need to know what a 'normal' year to year change is in the total amount of money in savings accounts. If normally people set aside billions of dollars in savings accounts, but set aside nothing last year, this might be evidence that people are saving less. If normally people are depleting their savings accounts by billions of dollars, but didn't deplete their savings at all last year, this is evidence that people are saving more. So if this is the intended meaning, then before anything else, we need to know how last year compares to previous years.
- the total amount of money set aside last year in savings accounts was the same as in previous years
If we interpret the sentence this way, then it would mean that if, in an ordinary year, the public sets aside a billion dollars in savings, they did that again last year. But if that's the intended meaning, I don't understand the argument at all. Say two years ago, people saved a billion dollars, and then tons of people lost their jobs. You'd expect those people who lost their jobs to save much less than before. So if overall, savings didn't change in aggregate, that would necessarily mean that employed people saved more. So the argument makes no sense -- the evidence supports the exact opposite conclusion of the one the argument draws.
There are other critical problems with the question: it reaches a conclusion about people whose 'jobs are secure' from evidence about "the general public," which presumably includes children, retirees, those with insecure jobs, and the unemployed. We'd need to know something about what all those people, the ones the conclusion isn't talking about, are doing to say anything at all about those with 'secure jobs'. When real GMAT CR questions draw a conclusion about a specific subset of a group from information about the group as a whole, that's almost always the error you're looking for. But it doesn't seem to be here. So to even evaluate the evidence, we need to know about groups besides those with 'secure jobs', which makes answers like B reasonable choices here.
It's also unclear why we're looking at savings accounts in particular. The cited evidence is meaningless unless we know that savings account deposits somehow correlate with the total amount people save. How are we to know people aren't putting their savings under a mattress, or in a chequing account, or in mutual funds? So that's yet another question we need an answer to before we could hope to evaluate the argument.
There is one criterion I would ordinarily find decisive for a question like this. The question doesn't give us any units -- we have no idea if people in this question are saving $100 per year or $1,000,000,000 per year. So if you got an answer to the question in answer choice B -- say you learned "people deplete $150 on average" -- there'd be no way to interpret that number. You don't have any other numbers to compare it with. The only single question that could provide useful numerical information would need to ask about a ratio or percentage, not about an absolute number. But I wouldn't rely on that criterion here, because I don't have any confidence in the overall logic of the question setup, so I wouldn't expect the question to observe logical subtleties like this one.
I'd suggest using official questions in general for Verbal practice, since you can rely on them to be logically airtight.