Aptitude - Boats and Streams
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.
What is the speed of the boat in still water?
The speed downstream is 12 kmph.
The speed upstream is 4 kmph.
In a to and fro journey between two points, the average speed of the boat was 6 kmph.
|From I and II, speed of boat in still water =||1||(12 + 4) km/hr = 8 km/hr.|
From II and III, we get:
|Using average speed =||2xy||, we get:||2 x 4 x y||= 6|
|x + y||4 + y|
8y = 24 + 6y
y = 12.
|Required speed =||1||(12 + 4) km/hr = 8 km/hr.|
Similarly, I and III also give the answer.
Correct answer is (D).