Dice probability statistics are pretty funny like that, actually. If a D50 existed, those would work OK too instead of 2d10s!
Check out the following rolls on anydice.com! The graph output shows the likelihood of 'any roll of the given values will land on that result'.
Dice probability statistics is how I know that the 'average roll on a d6' is 3.5 and that you should take a 3d4 (mean result 7.5) weapon over a 1d12 (mean result 6.5) ! Pays to know these things to help give players a subtle and useful edge over NPCs.