The women at Penn are way better than chicago. Although that is not saying much. Seriously, grad school is what counts, so your brother should just go to ASU and light up some honies. Get some A's and crush the GRE math subject test and he will be fine.
If you are not going to MIT/Caltech/Harvard/Yale, then go to ASU. Get laid, get A's. Then go to a good grad program.