I feel like it's worth pointing out, that whilst the "one mark a minute" approach is effective in some ways, don't feel obliged to commit to your time restraints.
For example, some multiple choice may take 20 seconds, and some may require 2 minutes as you read it again and think about the application. More so, with short answer, a 3 mark question may require a bit more than 3 minutes effort of writing to cover all the necessary points. Basically, if you feel the need to spend more time to cover yourself, do so, better to have more than less our teachers says.
Definitely, this method is good as a guide, but don't go on the "oh shit past my allocated time, move on" as each individual may differ in terms of required time and points necessary to gain the marks.
Also, our teacher always tells us to start with the short answer section first. The reason being is that usually requires a bit more thinking. Also, in the event your pushed for time, you can get lucky with quickly reading and answering multiple choice, but short answer, you can't exactly pull off the same marks with the reduced time.