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What is the average (arithmetic mean) of w, x, y, z, and 10?

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by M7MBA » Thu Mar 01, 2018 6:43 am
What is the average (arithmetic mean) of w, x, y, z, and 10?

(1) The average (arithmetic mean) of w and y is 7.5; the average (arithmetic mean) of x and z is 2.5
(2) -(-z - y -x - w) = 20

The OA is the option D.

How can I use statement (1) to get an answer here? Experts, may you help me? I'd be thankful.
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by mbawisdom » Tue Mar 06, 2018 6:07 am
M7MBA wrote:What is the average (arithmetic mean) of w, x, y, z, and 10?

(1) The average (arithmetic mean) of w and y is 7.5; the average (arithmetic mean) of x and z is 2.5
(2) -(-z - y -x - w) = 20

The OA is the option D.

How can I use statement (1) to get an answer here? Experts, may you help me? I'd be thankful.
We want to find out what (w + x + y + z + 10)/5 equals.

(1) tells us that (w + y)/2 = 7.5 or that w + y = 15, it also tells us that (x + z)/2 = 2.5 or that x + z = 5
Thus, we can use this to put into equation
(w + x + y + z + 10)/5
((x + z) + (w + y) + 10)/5
(5 + 15 + 10)/5
30/5
6
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by Jay@ManhattanReview » Wed Mar 07, 2018 3:01 am
M7MBA wrote:What is the average (arithmetic mean) of w, x, y, z, and 10?

(1) The average (arithmetic mean) of w and y is 7.5; the average (arithmetic mean) of x and z is 2.5
(2) -(-z - y -x - w) = 20

The OA is the option D.

How can I use statement (1) to get an answer here? Experts, may you help me? I'd be thankful.
We have to get the average (arithmetic mean) of w, x, y, z, and 10.

The average (arithmetic mean) of w, x, y, z, and 10 = (w + x + y + x + 10)/5.

If we get the value of (w + x + y + x), we get the answer.

Let's take each statement one by one.

(1) The average (arithmetic mean) of w and y is 7.5; the average (arithmetic mean) of x and z is 2.5.

=> (w + y)/2 = 7.5 => w + y = 15
=> (x + z)/2 = 2.5 => x + z = 5

=> w + x + y + x = 15 + 5 = 20. Unique answer. Sufficient.

(2) -(-z - y -x - w) = 20

=> z + y +x + w = 20. Unique answer. Sufficient.

The correct answer: D

Hope this helps!
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