There are 3/4 left in the third frame, so there are 60/(3/4)=80.

It puts 80* 1/4=20 in the second frame.

Then there are still 40 seconds to put in the frame, which is 2/3 of the original, so there is 40/(2/3)=60.

The first box is 60* 1/3=20,

Then the original 60-20=40 frames.

That's 40, 60, 80