May additional time in college harm my chances of going to grad school? I'm an electrical engineering major (my home university is ranked #25 nationally). I'm about to start the fifth year(engineering takes 5 years in my country).

I also granted a national science scholarship last year, and was an exchange student at University of Colorado at Boulder. I did very well over there (3.9/4.0).

In my country, electrical engineering and electronic/computer(EECS) science are different. Electrical deals with power systems and telecomunications, while EECS deals with microelectronics, dsp, embedded systems, theory of computation and so on.

My home university doesn't have the EECS option so I had to choose electrical engineering, since I hadn't money to move to another place.

at CU Boulder, I basically only took classes in advanced math (even grad school level) that is my passion for life and computer science(another passion). Since I got back I'm not very motivated with my program, because I want to study EECS and math and not power systems.

Currently I'm attending the math summer program(summer here is January and February) at one of the leading math research institutes in my country(and even one of the best in the world) and I was invited to start the Master of Advanced Studies in March. They offered me a scholarship, so all my expenses will be covered. Since I didn't complete my undergrad studies yet, they offered to transfer my Engineering course to the school of engineering and math(ranked #1 nationally), and then after 2/2.5 years from march I'd have a bachelor's of electronic/computer science engineering, a second bachelor's degree in math and Master of Advanced studies in math. The only "problem" is that in the end, I'd have taken 7/7.5 years to complete my bachelor's of engineering program.

My question is the following: Will this "long time" for completing the engineering program harm my chances of being accepted by grad school, in math or computer science in a top graduate school? 

May I argue in the applicant's form that I took 7.5 years because I moved on, I wasn't happy with my course/university, and when I chance to study my passions at the best schools in the country so I went forward ? (that would in fact be true)

In the whole thing I'd have 3 degrees(by # 1 institutes) in a total time of 7.5 years and a really good education, but I'm a little concerned about this "time to complete" thing, I really don't know how it works, specially in US

Can someone help?

Thank you everybody,

Dmitri
Taking a long time to complete one degree can be a bit of a red flag in US graduate admissions. However, this does not apply in your case, because you will have three separate degrees. The fact that you have transferred from one school to another also mitigates the lengthier time you've spent in those study programs.

If you hadn't done this "master of advanced studies," spending 7.5 years as an undergraduate would probably not be looked on too favorably. But in your specific circumstance, it's not as bad as it looks at first blush.

There might be a question, however, about why you want to do EECS at the graduate level, given that your master's degree would be in a math-related field. But that would be up to you to explain in any case as part of your statement of purpose.