Should i apply to columbia or duke early decision?

you said yourself that columbia is your dream school. you should of course apply to duke regular decision just in case something goes wrong, but i think columbia ED is a good idea. i'm slightly worried about your gpa because a bunch of Bs means that your unweighted (which is the important one) gpa is maybe not a 4.0. if your rank is still high (top 10 in your cl), then you should still have a good shot.