PrepTest 147

Incorrect. This answer can be very tempting. However, the stimulus is about the same program running on two different computers. As soon as you bring in a second program, that throws off the scenario described in the stimulus and the comparison can no longer be drawn. To highlight this, imagine a program that's really good at analyzing moves, but then always advances a pawn. That program wouldn't win against a semi-competent program.

Incorrect. The stimulus specifically notes that the comparison requires two computers with which a chess-playing program "is compatible," so, if anything, it is assuming that something about those computers can affect whether a program will run on it. That may not be speed, so we don't know this answer is false, but there is something in the stimulus that suggests it's not true.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Must Be True

Stimulus Summary:
For any two computers with the same chess-playing program installed and the same time limits, the faster one will win because it can consider more moves in that time.

Answer Anticipation:
This stimulus brings up many, many comparisons between any two chess programs.

It starts by saying that there's a way to compare them—have them play each other with fixed time limits. If you set the time limits to be equal, the faster computer will win. Why? Because it can examine more moves in the time it has.

Now, this stimulus—unlike most Must be True questions—features an argument. However, instead of questioning the conclusion, we accept it as true.

Here, for the conclusion to be true—for the faster computer to have a better chance at winning—it must be true that what we know about that computer compared to the slower one is relevant to that determination. What we know about it is that it can examine more moves in the allotted time. Therefore, it must be true that examining more moves increased the chances that a computer will win a chess match.

Note that this analysis was very similar to what we'd think about while working through a Strengthen with Necessary Premise question. If a premise is necessary for an argument to work, then it must be true for that argument to work. So in a Must be True question, where we are told to treat the conclusion as true—any necessary assumptions will be something that can be inferred.

Answer Explanation:
This answer matches our anticipation. The argument concludes that a faster computer will generally win at chess against a slower one because it can examine more moves. For that to be true, it must be true that examining more moves increases the chances that a computer will win a game of chess.

Key Takeaway:
If a premise is necessary for an argument to work, then it must be true for that argument to work. So in a Must Be True question, where we are told to treat the conclusion as true—any necessary assumptions will be something that can be inferred.

Incorrect. This answer deals with two separate chess-playing programs, not one running on two different computers. As such, it doesn't allow us to make an inference about the ability to examine moves—maybe one of the programs is more efficient and thus could run more calculations on a slower computer.

Incorrect. In changing up the time allotment, this answer changes up something that was integral to the comparison in the stimulus and thus isn't supported.