Inference
Boil it Down:
· New tech can increase productivity in existing coal mines
· Coal output per miner is doubled in 5 years
· Here, most likely the author is concerned with the
average coal output per miner
Which of the following can be
properly concluded from the statement about coal output per miner in the passage?
(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. – correct – pretty straightforward – think in terms equation. (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 – this is a trap – suppose some mine where output per miner did not increase, but they recruited more miners. Hence, total output will increase. But the output per miner will not - OUT
(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 – can’t be inferred - OUT
(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 – TRAP – suppose a mine who has recruited many new miners. Now, output per miner is almost stable, but the total overall output is likely to increase. - OUT
(E) In Tribnia
the cost of producing a given quantity of coal has declined over the past five years. – cost of producing coal is irrelevant.