energetics wrote:
buckkitty wrote:
That the application of new technology can increase the productivity of existing coal mines is demonstrated by the case of Tribnia's coal industry. Coal output per miner in Tribnia is double what it was five years ago, even though no new mines have opened.
Which of the following can be properly concluded from the statement about coal output per miner in the passage?
What we know ==> #coal per miner is now double compared to 5 years ago, 0 new mines
(A) If the number of miners working in Tribnian coal mines has remained constant in the past five years, Tribnia's total coal production has doubled in that period of time.GMATNinja VeritasKarishma When I read this AC, I thought total amount of coal would not necessarily double over the 5 year period if there was a downturn in one of the years -- that 2*ratio now at some point in the past was not true. Did I just confuse ratio and numerical value? Presumably the statement would need something like "now" or "this year" and "total amount of coal" to make it mean what I thought?(B) Any individual Tribnian coal mine that achieved an increase in overall output in the past five years has also experienced an increase in output per miner.First of all we can't talk about individual mines, out of scope. Also, it's possible they hired more miners so output could stay the same or even decline.
(C) If any new coal mines had opened in Tribnia in the past five years, then the increase in output per miner would have been even greater than it actually was. Could be true, but not must be true because the new mine could just have the same rate of output per worker and therefore output would stay the same.
(D) If any individual Tribnian coal mine has not increased its output per miner in the past five years, then that mine's overall output has declined or remained constant.Could be true only and out of scope as before. Can't talk about individual mines and increase in miners could increase overall output but have a reduced coal output per miner.
(E) In Tribnia the cost of producing a given quantity of coal has declined over the past five years.Obviously out of scope since price is not mentioned.
Coal per miner has doubled in the last 5 years. This means:
(Total Coal in 2019/ No of miners in 2019) = 2 * (Total Coal in 2014/ No of miners in 2014)
It is not necessary that it has increased every year. From 5 yrs ago to today, this is the status.
Option (A) tells us that No of miners has stayed constant. So
No of miners in 2019 = No of miners in 2014
This means Total Coal in 2019 = 2 * Total Coal in 2014
Hence option (A) holds.
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20 Aug 2019, 10:34
