What are the speeds of trains ‘A’ and ‘B’?
II. The speed of train ‘A’ is twice the speed of ‘B’.
II. Train A passes train B in 9 sec and its length is 100 m

Options
1) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
2) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
3) if the data in Statement I alone or in Statement II alone are sufficient to answer the question.
4) if the data, in both the Statements I and II together are not sufficient to answer the question.
5) if the data in both the Statements I and II together are necessary to answer the question.

• option 4, because we do not know the length of train B, so we cannot calculate speed of train A
• 7 years agoHelpfull: Yes(1) No(0)
• speed of A = 2(speed of B)
  a speed = d * t = 100 * 9 = 900m/s
  b speed = speed of A/2 = 450m/s
  
  So we need both I and II to answer as B 's speed is linked with A 's speed
• 8 years agoHelpfull: Yes(0) No(6)