GMAT Math

Hi RiyaR,

This is an example of a "symbolism" question - in these situations, you're given a "made-up" math symbol, told what it means, then asked to perform some basic calculation with it.

From what you've written, I assume that "ap3" is meant to be A(P^3).

#P# = A(P^3) + BP - 1 is the symbol/calculation we need to use.

We're told that #-5# = 3, so let's plug in -5 and see what we have...

A[(-5)^3)] +B(-5) - 1 = 3

-125A -5B = 4

Let's leave this for now and look at what we're asked to figure out....

#5# = ?

Now, let's plug in 5 and see what we have...

A(5^3) + 5B - 1
125A + 5B - 1

From earlier, remember that...
-125A - 5B = 4

Here we have....
125A + 5B
It's the same thing, but everything has the opposite "sign"...This tells us:

125A + 5B = -4

Plugging this value back in....
(125A + 5B) - 1
-4 -1 = -5

Final Answer: E

GMAT assassins aren't born, they're made,
Rich

Hi Jacob003,

If you're looking for additional Symbolism questions (or just broader Quant questions), then the OG13/GMAT2015 books are great sources (they are the SAME book though, so you don't need them both). There's also the GMAC Quant specific book. They're all available online and in most large bookstores.

As a "math" category, Symbolism questions are just off-shoots of arithmetic and algebra. You're given a symbol, told what it "means" mathematically and then asked to perform some basic math calculation using that symbol. You'll typically see 1 on Test Day (although you might randomly see an extra 1-2), so it's not a big category in and of itself.

GMAT assassins aren't born, they're made,
Rich