nah, lectures usually last from 5 past till 5 minutes to, giving you a 10 minute break to get between lectures.
Since your maths, stats and computer science lectures will either be in the maths building, boyd orr or computer science building (i imagine) you have 10 minutes to jump into the QM and get a coffee or a sandwich usually and then go back to your lecture.
That said, I hate having 2 lectures in a row let alone 3...