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26 May 2017, 04:43
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What is the median of a, b, 7.5 and 7.5?
(1) The average (arithmetic mean) of a and b is 7.5
(2) The sum of a and 2b is equal to the sum of b and 15
(1) The average (arithmetic mean) of a and b is 7.5
(2) The sum of a and 2b is equal to the sum of b and 15
26 May 2017, 04:44
Kudos
Bookmarks
Official Solution:
In the original condition, there are 2 variables (a,b). Since you need to match the number of variables to the number of equations, there should be 2 equations. Therefore, C is highly likely to be the answer. By solving con 1) &con 2), you get 1) = 2). In other words, for con 1) \(a + b = 7.5 * 2 = 15\) and for con 2) \(a + 2b = b + 15\), both becomes \(a + b = 15\). In any case including \((a,b)=(7.5, 7.5),(7.0,8.0)\ldots\) .., the median always becomes \(\frac{7.5+7.5}{2} = 7. 5\), hence, unique and sufficient. Therefore, the answer is D.
Answer: D
In the original condition, there are 2 variables (a,b). Since you need to match the number of variables to the number of equations, there should be 2 equations. Therefore, C is highly likely to be the answer. By solving con 1) &con 2), you get 1) = 2). In other words, for con 1) \(a + b = 7.5 * 2 = 15\) and for con 2) \(a + 2b = b + 15\), both becomes \(a + b = 15\). In any case including \((a,b)=(7.5, 7.5),(7.0,8.0)\ldots\) .., the median always becomes \(\frac{7.5+7.5}{2} = 7. 5\), hence, unique and sufficient. Therefore, the answer is D.
Answer: D
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