I have heard that MIT has a different school for business and engineering. Is it possible to be a part of the business school and the engineering school in order to double major?
MIT is made up of five schools (Science, Engineering, Humanities/Arts/Social Sciences, Sloan School of Management, Architecture/Planning), but they're just administrative units -- the fact that they're separate schools doesn't really affect you in any way as a student. You can double-major within or between schools with no problems whatsoever.