To be honest, I am very bad at multitasking. I always end up switching the tasks. Complete one peacefully, do the justice to the work and then move on.
I think most of the time, people would expect you to finish n number of tasks within a certain time period. The best thing to do in such cases would be to divide your time by n and then proceed.
This would give you an idea whether it’s possible to finish all the n tasks in x time.