Official Guide 13th Ed, Data Sufficiency #118

gth8785 wrote:Leave the answer I did not understand the question in the first place.
Please help and explain in simple language

We refer to this as a "strange operator" question. For these question types you are introduced to some new kind of symbol. (Aside: remember when you were first introduced to the square root symbol? At first, you didn't know what it meant, and now you do.)

The strange operators here are "max" and "min."
The "max" operation basically says, "take the 2 given values in the brackets and output the greatest one.
So, for example:
max(8, 3) = 8, since 8 is the larger of the two values
max(-3, 4) = 4, since 4 is the larger of the two values
max(-1, 0) = 0, since 0 is the larger of the two values
etc.

The "min" operation says, "take the 2 given values in the brackets and output the smallest one.
So, for example:
min(8, 3) = 3, since 3 is the smaller of the two values
min(-2, 6) = -2, since -2 is the smaller of the two values
min(-5, -7) = -7, since -7 is the smaller of the two values
etc.

Cheers,
Brent

gth8785 wrote:For any integers x and y, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively.
For example, min(5, 2) = 2 and max(5, 2) = 5. For the integer w, what is the value of min(10, w)?

(1) w = max(20, z) for some integer z.

(2) w = max(10, w)

Target question: What is the value of min(10, w)?

Statement 1: w = max(20, z) for some integer z.
Let's take a closer look at max(20, z)
If z < 20, then max(20, z) = 20
If z > 20, then max(20, z) = some value greater than 20
So, max(20, z) must be greater than or equal to 20
Since, w = max(20, z), we can conclude that w is greater than or equal to 20
From this, we can conclude that min(10, w) = 10, since 10 will be the lesser value
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: w = max(10, w)
If w = max(10, w), then w is the larger value.
In other words, w is greater than or equal to 10
If w is greater than or equal to 10, then we can conclude that min(10, w) = 10
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer = D

Cheers,
Brent

gth8785 wrote: I've never had Math as a subject after 10th grade, thus I'm having a tough time doing GMAT quant.

You're not alone

Cheers,
Brent