What is the speed of the boat in still water? It takes 2 hours to cover the distance between A and B downstream. It takes 4 hours to cover the distance between A and B upstream.

Options

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 to question.
B. if the data in statement Ii alone are sufficient to answer the questin, while the data in statemetn I alone are not suffcient to answer the question.
C. if the data wither in statement I alone or in statement II alone are sufficient to answer the question.
D. if the data event in both the statements I and II together are necessary to answer the question.

Answer

D

Explanation

Let the distance between A and B be z km.
Again, let speed of boat in still water be x kmph and that of stream be y kmph.
`therefore` Rate downstream `=(x+y)` kmph
Rate upstream `=(x-y)` kmph
From statement I,
`(z)/(x+y)=2" "...(i)`
From statement II,
`(z)/(x-y)=4" "...(ii)`
we have two equations and three variables, therefore both equations are not sufficient.