Multiple choice

What is the speed of the second train? I. Two trains of equal length cross each other in 12 seconds when moving in opposite directions. II. The speed of the first train is 60 km/h and its length is 360 metres.

  1. The data in statement I alone is sufficient to answer the question, while the data in statement II alone is not sufficient to answer the question.

  2. The data in statement II alone is sufficient to answer the question, while the data in statement I alone is not sufficient to answer the question.

  3. Both statements (I) and (II) together are sufficient, but neither statement alone is sufficient.

  4. The data in both the statements I and II together is not sufficient to answer the question.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement I gives the relative speed (2*length/12). Statement II gives the length and speed of one train. Together, these allow solving for the speed of the second train.

AI explanation

From statement II, the length of the first train is 360 meters, meaning the total length of both trains is 720 meters. Using statement I, their relative speed is 720 divided by 12, which equals 60 meters per second, or 216 kilometers per hour. The speed of the second train is found by subtracting the first train's speed of 60 kilometers per hour from this relative speed, so both statements together are necessary to answer the question.

Keep practicing — related questions