Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.
1. | What is the speed of the train? I. The train crosses a signal pole in 18 seconds. II. The train crosses a platform of equal length in 36 seconds. III. Length of the train is 330 metres. | |||||||||||||||||||||||||||||||||||
Answer: Option D Explanation: Let the speed of the train be x metres/sec. Time taken to cross a signal pole :
Time taken to cross a platform
Length of train = 330 m. I and III give,
II and III give,
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2. | What is the speed of the train? I. The train crosses a tree in 13 seconds. II. The train crosses a platform of length 250 metres in 27 seconds. III. The train crosses another train running in the same direction in 32 seconds. | |||||||||||||||||||||||||||
Answer: Option A Explanation: Let the speed of the train be x metres/sec.
Time taken to cross a platform
Thus I and II give the speed of the train. View Answer | Workspace | Report | Discuss in Forum |
3. | What is the speed of the train? I. The train crosses 300 metres long platform in 21 seconds. II. The train crosses another stationary train of equal length in 19x(1/2) seconds. III. The train crosses a signal pole in 9x(3/4) seconds. | |||||||||||||||
Answer: Option B Explanation: Let the speed of the train be x m/sec. Time taken to cross a signal pole
Time taken to cross a platform
I gives, 21 = (l + 300)/x; II gives, 39/2 = 2l/x; III gives, 39/4 = l/x. Thus, (I and II) or (I and III ) give x. Correct answer is (B) View Answer | Workspace | Report | Discuss in Forum |