For PPE you don't actually have to do any of the three disciplines. However, I would recommend you take Economics. Politics and Philosophy are not required as long as you are willing to read around them. I'd definitely recommend History, and Maths (which for some is a requirement, for others it isn't, but nearly everyone takes it). If you do not like Maths, you have to consider that PPE is not the degree for you. I'd recommend: History, Economics, Maths, and one other which is at least respectable and you think you would both enjoy it, and be good it. I'd then recommend you take History, Economics, and Maths for A2.