GMAT Videos

This looks like something where we ought to be able to square the second equation as it stands–but that will give you a polynomial with a root in the middle. Bad. However, if you look at the left equation as a difference of squares (where the right equation is one of the two brackets), then … Read More

The function f is defined for each positive three-digit integer n by , where x, y and z are the hundreds, tens, and units digits of n, respectively. If m and v are three-digit positive integers such that then ? (A) 8(B) 9(C) 18(D) 20(E) 80 The real trick here is to think about f(m) … Read More

Look at what you’re trying to do: reduce the amount of ash by reducing the number of truckloads. Fewer truckloads does not necessarily mean less ash. If you were the corporate lawyer, your job would be to figure out how to reduce the number of truckloads while keeping the amount of ash exactly the same. … Read More