Data Sufficiency

Hi All,

We're told that a zebra must get water from either a stream or pond. We're asked which of the two sources of water is closer to the zebra's current position.

1) Moving at a constant rate, it takes the zebra 2 hours to reach the stream from its current position.

Fact 1 tells us nothing about what this 'constant rate' is, so there's no way to determine the zebra's distance from the stream. We also know nothing about the zebra's distance from the pond.
Fact 1 is INSUFFICIENT

2) Moving at a constant rate, it takes the zebra 2 hours to reach the pond from the stream.

Fact 2 tells us nothing about what this 'constant rate' is, so there's no way to determine the zebra's distance from the pond. We also know nothing about the zebra's distance from the stream.
Fact 2 is INSUFFICIENT

Combined, we know...
-Moving at a constant rate, it takes the zebra 2 hours to reach the stream from its current position.
-Moving at a constant rate, it takes the zebra 2 hours to reach the pond from the stream.

Unfortunately, we don't know if the two 'constant rates' that are mentioned are the same OR not, so there's no way to gauge the relative distances to the stream and pond.
IF the two rates are equal, then the distances of the two water sources would be the same.
IF one rate is faster than the other, then the distance of the water source would be farther away than the other source.
Combined, INSUFFICIENT

Final Answer: E

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorLU wrote:Source: Princeton Review

A zebra must get water from either a stream or pond. Which of the two sources of water is closer to the zebra's current position?

(1) Moving at a constant rate, it takes the zebra 2 hours to reach the stream from its current position.
(2) Moving at a constant rate, it takes the zebra 2 hours to reach the pond from the stream.

The OA is E

Target question: Which of the two sources of water is closer to the zebra's current position?
Jump straight to....

Statements 1 and 2 COMBINED
There are several scenarios that satisfy BOTH statements. Here are two:
Case a: When traveling to the STREAM, the zebra heads EAST in a straight line at a constant speed of 1 mile per hour. So, the STREAM is 2 miles away from the zebra's starting point. When traveling from the STREAM TO THE POND, the zebra heads EAST at a constant speed of 1 mile per hour. So, the POND is 4 miles away from the zebra's starting point.
In this case, the answer to the target question is the STREAM is closer to the zebra

Case b: When traveling to the STREAM, the zebra heads EAST in a straight line at a constant speed of 1 mile per hour. So, the STREAM is 2 miles away from the zebra's starting point. When traveling from the STREAM TO THE POND, the zebra heads WEST at a constant speed of 1 mile per hour. So, the POND is 0 miles away from the zebra's starting point.
In this case, the answer to the target question is the POND is closer to the zebra

Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent

Unfortunately, we don't know if the two 'constant rates' that are mentioned are the same OR not, so there's no way to gauge the relative distances to the stream and pond.
IF the two rates are equal, then the distances of the two water sources would be the same.
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Even if the zebra's speed is the same in both cases, we can't conclude anything about the distances, since we aren't told anything about the direction the zebra is traveling. It may even be the case that the zebra is traveling in circles

Cheers,
Brent