In you project bin select your clip(s). Rit click them. Select 'modify' and then 'interpret footage.' On the pop up there is a option to 'assume frame rate is ___ fps' (or something along those lines).
Put in 24 fps on that and make sure it's actually selected. Now if you put your clips down on the a 24fps sequence they will pick be slow motion. I typically shoot sports so I change speed a lot so I will select all my clips. Hit Apple-R and change the speed to 250%.