Multiple choice

A boat takes 36 minutes to travel from Harbor A to Harbor B along a fixed route. How long does it take for the boat to return from Harbor B to Harbor A along the same route? (1) The boat's average speed from A to B is 80% of its average speed from B to A. (2) The distance between the harbors is 9 nautical miles.

  1. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

  2. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

  3. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

  4. EACH statement ALONE is sufficient.

  5. Statements (1) and (2) TOGETHER are NOT sufficient.
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A Correct answer
Explanation

The time taken for a trip depends on speed and distance. Statement (1) provides the ratio of speeds, which allows us to relate the time taken for the return trip to the time taken for the initial trip. Statement (2) is irrelevant because the actual distance cancels out when calculating the time ratio.

AI explanation

Using the formula time equals distance divided by speed, the return time equals the forward time multiplied by the ratio of the forward speed to the return speed. Statement (1) states the forward speed is 80% of the return speed, meaning the ratio of forward speed to return speed is 0.8, so the return time is 36 minutes multiplied by 0.8, which equals 28.8 minutes. Statement (2) gives the distance as 9 nautical miles but provides no information about the return speed, making it impossible to find the return time. Therefore, statement (1) alone is sufficient, but statement (2) alone is not sufficient.

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