Should I get an iPad or repair my laptop?

I have a 2007 MacBook pro that died on my last week. It is past the warranty period and has a faulty logic board that can be replaced for $650. I am an engineering student in college and do most of my work on my iMac, so I really only need word processing on it. I did use matlab and autocad on it, but since I have them on my desktop, it's not absolutely necessary I have it on my laptop. I really just need to type notes in class. I would definitely get the keyboard for the ipad too. My dad works for apple so I can get a 25% discount on an iPad or another MacBook. Will an iPad suffice for what I need it for, should I fix my MacBook pro, or should I get the new 13" MacBook pro?