how do I make a Time Based Score System?

I am making a game , however I am still fairly new to scripting and I don’t now how to implement this.
I am trying to make a score system that works with a timer/stopwatch. For example , every second that passes, points are lost…faster level is completed, the more score is
awarded, the standard amount of time per level is 2 minutes :

Time at EndLevel

Time = 1:00 Score = 100
Time = 0:50 Score = 80
Time = 0:40 Score = 60
Time = 0:00 Score = 0

and so on…

alternately if its easier , it could be done as more Time = Less Score?

and where would I attach the script to and how would I go about showing this on the GUI?

Thanks in advance and I sincerely apologise for my NooBness!


You could try something like this:
score = 100;
score = score - Time.deltaTime;
So as time advances the score diminishes.