So for several months I have been busy studying for the GMAT which I'll be taking this coming Saturday. Today I took a prep. test and I am just blown away by how hard it is. The prep test is much harder than the math problems that I solved in the books I have been studying. I was wondering if you could help me solve a couple (or more) of these problems that are giving me a really hard time so that I could be as prepared as I possibly can. Thanks in advance for any help.
Q: If 5^21 x 4^11 = 2 x 10^n, then what is n?
Just in case...the ^ symbol represents exponent. Using a calculator I can work this out, but in the test I can't use a calculator. Anyone know of a shortcut? Thanks.