You work on 60th floor of 100 story building. You walk into your office and find a bomb sitting on your desk. It reads 90 seconds and is counting down. What do you do?

I would keep calm because it is obviously a fake bomb. Bombs with big countdown displays only happen in the movies.

Pull the nearest fire alarm to get people out of the building as quickly as possible, then get the bomb to a corner and place myself on the opposite side of the floor (or inside a fire escape, which is thicker than drywall)

I will go the top of the building (roof) , which might take maybe 60 seconds (assuming the lift is not too slow), and when 6 seconds are remaining, I will throw it diagonally away (as high as I can and as far from the building as I can) so that it explodes Mid air which significantly reduces the probability of any kind of damage or loss.

Break a window, and throw it out?