Bunuel
If a and b are both integers greater than 0 and the average (arithmetic mean) of the values above is 3, which of the following is a possible value for the median?
1, 4, a, 5, b, 4
(A) 1.5
(B) 2
(C) 2.5
(D) 3
(E) 4
The average (arithmetic mean) of the values above is 3So, we can write: \(\frac{1 + 4 + a + 5 + b + 4}{6} = 3\)
Multiply both sides of the equation by \(6\) to get: \(1 + 4 + a + 5 + b + 4 = 18\)
Simplify: to get: \(a + b + 14 = 18\)
Subtract \(14\) from both sides:
\(a + b = 4\)Since we're told \(a\) and \(b\) are POSITIVE integers, there are only two possible pairs of values for \(a\) and \(b\).
Let's examine each possible case....
Case i: The two numbers could be
1 and
3, in which case the six numbers (when displayed in ascending order) are {1,
1,
3, 4, 4, 5}
In this case, the median = 3.5
Since 3.5 does not appear among the answer choices, we'll check case ii
Case ii: The two numbers could be
2 and
2, in which case the six numbers (when displayed in ascending order) are {1,
2,
2, 4, 4, 5}
In this case, the median = 3
Answer: D
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