Multiple choice

What will be the speed of the stream, if the speed of the boat in still water is 22.5 km/hr? A. The time taken by the boat to cover 120 km upstream is 4 hours more than the time taken by the boat to cover the same distance downstream. B. The boat takes a total of 15 hours to cover 150 km downstream and upstream.

  1. Statement A alone is sufficient to answer the question but statement B alone is not sufficient to answer the questions.

  2. Statement B alone is sufficient to answer the question but statement A alone is not sufficient to answer the question.

  3. Both the statements taken together are necessary to answer the questions, but neither of the statements alone is sufficient to answer the question.

  4. Either statement A or statement B by itself is sufficient to answer the question.

  5. Statements A and B taken together are not sufficient to answer the question.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let stream speed = s. Speed downstream = 22.5+s, upstream = 22.5-s. Statement A: 120/(22.5-s) - 120/(22.5+s) = 4. One variable, solvable. Statement B: 120/(22.5-s) + 120/(22.5+s) = 15. One variable, solvable. Each alone sufficient. Answer D is correct.

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