Boats and Streams – Data Sufficiency 2
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.
Answer: Option D
Explanation:
| From I and II, speed of boat in still water = | 1 | (12 + 4) km/hr = 8 km/hr. |
| 2 |
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. |
| 2 |
Similarly, I and III also give the answer.
Correct answer is (D).