Question

What is the speed of the goods train?

I. 420 metres long goods train crosses a signal pole in 27 seconds.

II. 420 metres long goods train crosses a platform in 67.5 seconds.

• A. 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.
• B. 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.
• C. if the data either in Statement I or in Statement II alone are sufficient to answer the question.
• D. if the data even in both Statements I and II together are not sufficient to answer the question.
• E. if the data in both Statements I and II together are necessary to answer the question.

Answer 1

The correct option is A

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.

$Speed=\frac{Lengthofthetrain}{Timetakentocrossthepole}=\frac{420}{27}m/s=\frac{140}{9}m/s.$

$\therefore$I alone gives the answer.

$Timetakentocrosstheplatform=\frac{\left(Lengthoftrain+Lengthofplatform\right)}{Speedofthetrain}$
$\Rightarrow Speed=\frac{\left(420+p\right)}{67.5}m/s.$

But, p = length of platform is not given.

$\therefore$ II alone is not sufficient to give the answer.