How do i change this number to a random number within a set time?

I know almost nothing about C, so I need a hand with this. So, I have a title and I want the numbers to change to a random number within a min# and a max#(for instance, 1-10) and I want it to change randomly within a given set time (for instance, randomly between 20-60 seconds it will change). As I said, im very new so im not sure where to look or anything. Thank you.