Multiple choice

How much time does Mr. Richards take to reach his office from home? (1) One day, he started 30 minutes late from home and reached his office 50 minutes late, while driving 25% slower than his regular speed (2) He needs to drive at a constant speed of 25 miles per hour to reach his office just in time if he is 30 minutes late from home.

  1. if statement (1) ALONE is sufficient to answer the question but statement (2) alone is not sufficient;

  2. if statement (2) ALONE is sufficient to answer the question but statement (1) alone is not sufficient.

  3. if the two statements TAKEN TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient;

  4. if EACH statement ALONE is sufficient to answer the question;

  5. if the two statements TAKEN TOGETHER are still NOT sufficient to answer the question
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A Correct answer
Explanation

Statement (1) allows us to set up equations for regular speed and time. Let T be regular time and S be regular speed. D = S*T. New scenario: D = 0.75S * (T + 50/60). Since D is constant, S*T = 0.75S * (T + 5/6). This allows solving for T. Statement (2) is also sufficient but (1) alone is sufficient.

AI explanation

Using statement one, let the usual time taken be t minutes. Since driving 25 percent slower means his speed becomes three-fourths of normal, his time becomes four-thirds of normal, so four-thirds of t equals t plus 20, which solves to t equals 60 minutes. The second statement only provides a hypothetical speed but does not give any information about the usual time or distance, so it cannot be used alone. Thus, the first statement alone is sufficient, while the second is not.

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