Unfortunately, it depends. If you look in the FCTM under descent you can see the descent rates for various speeds, which gives an approximate descent angle. In general, the airplane will do close enough to a 3 degree glide with constant speed at up speed, 1 speed and 5 speed (slightly steeper with more flaps or higher speed). So a 3.3 degree V/B might work with 50NM to go and 290kts, but wont work with even a slight tailwind close in. I usually fly with the FPA on, so I can monitor actual descent angle and compare that to what I need (calculated with the times 3 table and/or V/B). Then manage the drag with speed if able further out, speedbrakes if needed and config close in. And if you completely cock it up the aircraft can do a double glide in landing config, so level off, get everything hanging out and see if you need to buy the other pilot a beer :-).