Question

Two towns are connected by railway. Can you find the distance between them?
I. The speed of the mail train is 12 km/hr more than that of an express train.
II. A mail train takes 40 minutes less than an express train to cover the distance.

• A. I alone sufficient while II alone not sufficient to answer
• B. II alone sufficient while I alone not sufficient to answer
• C. Either I or II alone sufficient to answer
• D. Both I and II are not sufficient to answer
• E. Both I and II are necessary to answer

Answer 1

Answer: (D)

Both I and II are not sufficient to answer

Let the distance between the two stations be x km.
I. Then, speed of the mail train = (y + 12) km/hr.
II. $\frac{x}{y-2}\frac{x}{y}=\frac{40}{60}$
Thus, even I and II together do not give x.
$\therefore$ Correct answer is (D).