Timing cuts to a clock

[charles5EA1]

I am fairly new to premiere pro - so forgive me if this is a little silly:

When timing cuts that all need to last a certain length - could someone explain why it skips from 1.29 to 2. I know it is something to do with frame rate but I don't understand how to change a clip to 1 and half seconds exactly and some clips to one and 3/4 seconds. 

[Peru Bob · Accepted solution]

1:29 means 1 second and 29 frames, not 1.29 seconds.

If your timeline is 30 Frames Per Second, then the next frame after 1:29 is 2:00.