LSAT Explanation PT 20, S1, Q24: Each December 31 in Country Q,

LSAT Question Stem

If the statements above are true, which one of the following must also be true on the basis of them? 

Logical Reasoning Question Type

This is a Must Be True question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

This is a Must Be True (MBT) question, which means we need to identify the statement that must be true based on the given information in the passage. Let's first break down the passage and clarify any confusing parts.

The passage tells us that in Country Q, a tally is made at the end of each year to determine the total available coal supplies, which is the total amount of coal mined but not consumed. It's important to note that this tally is a running tally, meaning it includes the leftover coal from previous years. The passage also tells us that the tally in 1991 was lower than in 1990 and that Country Q has not imported or exported coal since 1970.

Now, let's analyze the answer choices based on the information in the passage.

a) In Country Q, more coal was mined in 1990 than was mined in 1991.

- This statement is incorrect because the passage does not provide enough information to determine the amount of coal mined in each year. The change in the tally could be due to changes in production or consumption.

b) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.

- This statement is correct because the passage tells us that the tally in 1991 was lower than in 1990, which means that Country Q used more coal than it produced in 1991. Thus, this statement must be true.

c) In Country Q, the amount of coal consumed in 1990 was greater than the amount of coal consumed in 1991.

- This statement is incorrect because the passage does not provide enough information to compare the coal consumption in 1990 and 1991. The change in the tally could be due to changes in production or consumption.

d) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal consumed in 1990.

- This statement is incorrect because, as mentioned earlier, the passage does not provide enough information to compare the coal consumption in 1990 and 1991. The change in the tally could be due to changes in production or consumption.

e) In Country Q, more coal was consumed during the first half of 1991 than was consumed during the first half of 1990.

- This statement is incorrect because the passage does not provide any information about coal consumption during specific periods within a year.

Based on our analysis, the correct answer choice is (B): In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.