[email protected] wrote:The definition of mode is given in different ways.
For example,
Let A = {1,1,2,2,3,3}
As for few references Mode of the set A is given by 1,2,3 i.e., each element is mode, since each element is equally repeated.

But from few other references,
Mode = 3mean - 2 median
so, for set A
mean = 2
median = 2
mode = 2

so, finally which is correct answer.
Mode = 1,2,3
or
mode =2


So, as per GMAT which is correct answer?

Technically, if each value in a set occurs equally often, the set is considered to have no mode at all. So in the sets {1,2,3,4} and {3,3,3,4,4,4,5,5,5}, there is no mode. When one or more values occur more often than other values, the set will have one or more modes. So the set {1,2,2,2,2,2,2,2,2,3} has a mode of 2, and the set {5,5,6,7,7} has two modes, 5 and 7.

I'm not sure where you got the formula relating the mode, mean and median (mode = 3*mean - 2*median), but if it is true at all, it's only true for a very specific kind of distribution of data. It's certainly not true in general, and will not be true for the sets you see on the GMAT. You should just forget about that formula.

All of that said, the GMAT does not test technicalities of definitions, so you won't ever be asked the (meaningless) question "What is the mode of the set {1,1,2,2,3,3}?" I can't remember the last time I saw a real GMAT question that even mentioned the mode, in fact, so I very much doubt you'll encounter a mode question on test day.