Randoms numbers on iPhone

What is better? I have the prioritized in the order of "goodness", am I correct?

1. arc4random
2. randmom
3. rand

1 - best, 3 - worst

I need a really good randmon number gen for a lowe number (< 50), so I using % 50 to obtain numbers below 50.

Thanks

I'm pretty sure randMOM is the one to use.

Oh, well, first google hit.

If you need a number in the range [n, m), the very best approach is to use a function explicitly designed to do so. Both scaling (from say [0, 1)) and applying a modulus may slightly alter the distribution. Of course, such skewing may be entirely irrelevant (and for most applications is probably only a theoretical consideration) -- especially if only a basic PRNG is employed.