View Full Version : General Homework Help

06-01-12, 12:13
I couldn't find a thread on this and am in serious need for some math help at the moment :p

So here's the problem: For all numbers x and y, (x,y)! Is defined as the average of x and y. (2,10)!-(2,2)!

The answer choices are:

Any help is greatly appreciated as I have no idea where to start.

06-01-12, 13:11
First of all, a weird notation.

Second: Calculate all the (x,y)!s that are there anywhere. Make a long list if it helps. Then you can easily calculate (2,10)!-(2,2)!. After that, it is just a simple matter of comparing with the results for the answer choices.

A hint to cut it short: If both x and y are even or both odd, then the result will be even. Otherwise it will be odd. That means there are only two answer choices that could possibly work, and it is quickly obvious that it cannot be one of them.

06-01-12, 19:48
I appreciate the help and I was able to find the solution :) now I hope this thread is helpful to others in need of some homework help :D