Answer:
Probability and genes (look below)
Step-by-step explanation:
It depends on your genes. If both of you parents are right handed, you'll be right handed as well. If one is left handed and the other is right handed, there a 50-50 chance you'll be either. However, if, lets say, your grandparents from your dads side (his parents) are one right and one left handed, and hes right handed, you could be left handed, even if your mom is right handed. If you want to know THAT probability, I'd bore you to death with x and y chromosones (spelling lol) and punnett squares.