What is the speed of the stream?
I. The ratio of speed in upstream to the speed in downstream is `2:3`
II. The distance travelled in upstream in 2 hours by a man is more than distance travelled by him in downstram in 1 hour by 4 km.

Options

A. The data in Statement I alone are sufficient to answer the quenstion, while the data in statement II alone are not sufficient to answer the question.
B. The data in statement I alone or in statement II alone are sufficient to answer the question.
C. The data either in statement I alone or instatement II alone are sufficient to answer the question
D. The data even in both the statements I and II together II alone not sufficient to answer the question.

Explanation

From statement I,
given: The rato of speed in upstream to the speed in downstream is `2:3`
Let speed in upstream be 2x km/hr and speed in downstream be 3x km/hr.
Since x is not known, so speed of the stream cannot be obtaines.
Thus, the data in Statement I alone are not sufficient to answer the question
From statement II,
Given: The distance travelled in upstream in 2 hours by a man is more than distance travelled by him in dowstream in 1 hour by 4km.
`implies` distance travelled in upstream `-1xx` speed in upstream) = 4 km
`because` Speed in upstream and downstream is not known, so speed of the stream cannot be found using these data. Thus, the data in Statement II alone are not sufficient to answer the question
Combining I and II,
Speed in upstream `=2x`
Speed in downstream `=3x`
(`2xx` speed in downstream `-1xx` speed in upstream) =4km
`implies(2xx3x1xx2x)=4m`
` implies6x-2x=4`
`impliesx=1km//hr`
`therefore` Speed in upstream and downstream are 2 km/hr and 3 km/hr respectively.
Speed of the stream `=1//2` (speed in downstream - speed in upsteam)
`=1//2(3-2)`
`1//2km//hr`