Question: Directions: Each of the questions below consists of a question and three statements I, II and III given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. [IBPS (PO) 2012]
What is the speed of train?
I. The train crosses a signal post in 20 s.
II. The train crosses a 260 m long platform in 33 s.
III. The train crosses another stationary train of same length in 40 s
Options:
A) I and III
B) II and either I or III
C) All I, II and III
D) Any two of the three
E) Even with all three statements answer cannot be given
Show Answer
Answer:
Correct Answer: B
Solution:
- Let the length of train be x m and Its speed be
y m/s.
I. $ \frac{x}{y}=20 $
(i)
II. $ \frac{x+260}{y}=33 $
(ii)
III. $ \frac{2x}{y}=40 $
(iii)
Clearly, II and either I or III are necessary to answer the question.