# QR: Would the DAT do this?

#### slayerdeus

##### Member
10+ Year Member Yeh so I found the common denominator got answer D. However I marked answer B, that is SOOO mean, would the DAT really put an answer like this or would they be nice and put the x in the nominator?

#### JohnDoeDDS

##### Senior Member
10+ Year Member
7+ Year Member
ouch. I dunno if they would put it on the DAT just be mroe careful now that you know it "might" be there.

#### tinman831

##### ¯\_(ツ)_/¯
Staff member
10+ Year Member
This is really a simple question that, unless you are careful, you can miss. Getting the 11/18x is easy, but when you scan through the answers, and you happen to come across (11/18)x first, you might just select this answer in haste without realizing the 'x' is in the wrong place. A lot of questions on the DAT will have similar answers like this to trick you. You just have to keep an eye out for questions like this.

#### lizjunk

##### Hammie the squirrel
10+ Year Member
5+ Year Member
Wait, how do you even get the answer first of all?

#### tinman831

##### ¯\_(ツ)_/¯
Staff member
10+ Year Member
The average of any set of n numbers is the sum of those numbers divided by n.

The average of a, b, and c, is (a+b+c)/3.

In the problem you would first find a common denominator (which is 6x).

1/x, 1/2x, and 1/3x would then change to 6/6x, 3/6x, and 2/6x.

After you find a common denominator, you can add up the numbers.

6/6x + 3/3x + 2/6x = 11/6x

You take the sum and divide by the number of numbers in the set.

(11/6x)/3 = 11/18x 