HI, I was reading an article and it says that a finite group of order [itex]p^aq^b[/itex], where p, q are primes, is solvable and therefore not simple. But I can't quite understand why this is so. I do recall a theorem called Burnside's theorem which says that a group of such order is solvable. But then I don't see how it follows that the group is simple. Could someone please explain? Thanks.