Question

A bus crosses a traffic signal post in 10 seconds. What is the length of the bus?

I. The bus crosses a platform of 75 metres in 20 seconds.

II. The bus is running at the speed of 60 kmph.

• 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 C

if the data either in Statement I or in Statement II alone are sufficient to answer the question.

Let the length of the bus be `l' metres.

Time taken to cross a signal post $=\frac{Lengthofthebus}{Speedofthebus}\Rightarrow 10=\frac{1}{Speed}$ ..... (i)

Time taken to cross the platform $=\frac{(l+75)}{Speed}\Rightarrow 20=\frac{l+75}{Speed}$ ...... (ii)

Thus, from (i) and (ii), we can find `l'.

Also, II gives, speed $=(60\times \frac{5}{18})m/s=\frac{50}{3}m/s$.

Thus, the data in I or II alone are sufficient to answer the question.