Jane Said:

Can you help with difficult gmat math question?

We Answered:

5^21 x 4^11 = 2 x 10^n

here the idea is to make both side of the equation that looks similar and left side should be something like 2x10^x

5^21 x 4^11 = 2 x 10^n
or, 5^21 x 2^2x11 = 2 x 10^n
or, 5^21 x 2^22 = 2 x 10^n
or, 5^21 x 2^(21+1) = 2 x 10^n
or, 5^21 x 2^21x2^1) = 2 x 10^n
or, (5x2)^21 x2 = 2 x 10^n, similar powered terms can be multiplied,
or, 2x10^21 = 2x 10^n

So, by power equality, we get n = 21

Jacqueline Said:

how different is the gmat math and verbal compared to that of the sat?

We Answered:

The math is not harder really, in terms of the concepts covered, but the standard is higher and the questions are trickier. The reading part of the verbal is a bit harder, not much. The sentence correction is no harder. I don't know about the critical reasoning, but I'd guess it's a bit harder.

If you've been to university since doing the SAT, I'd say the 1300 is about the same as a 650.

Zachary Said:

How important is math on the gmat?

We Answered:

There is no calculus on the GMAT.

But the math questions are important, and they draw from high school mathematics, excluding calculus. The problems can still be quite challenging, so it helps to get as much practice as possible with examples before the exam.

Ivan Said:

I am not good in Math. How do I prepare for the GMAT?

We Answered:

All the previous posters made valid posts. The general consensus is that Barron's is a poor prep guide. You without a doubt need the GMAT Official Guide by the GMAC. The GMAC is the creator of the GMAT and the Official Guide provides actual (past) GMAT problems. Also, make sure you go to the MBA.com website and download the free test prep software (also made by the GMAC). You would most likely benefit from the The Princeton Review's Cracking the GMAT, which contains great review sections and test strategies.

Other popular study guides are Kaplan (tougher) and Manhattan. If you have the time and money, you might benefit from taking a GMAT prep course, in class or online. The aforementioned companies offer such courses.

Whatever resources you choose, repetitive practice is key. You must get the timing of the test down- this is where the full lenght practice tests will come in handy.
Good luck!