uncle_rico
Just to add a little bit to what Johnny has said.
If you choose one of the two transmittable resolutions of video, then that is the resolution that is recorded on the SD card. I overestimate the size of daytime 10 second 1024 * 576 videos at 6 MB. I've checked the size of quite a few and all have been under 6 MB.
I don't find the three shot burst very useful. If there were a long delay, so that you get a pic, then another in a couple of seconds, and another in a couple of seconds, that might be useful, but three one right after the other doesn't give me much information. Photo + video usually gives you a lot more information. The video starts 2 seconds after the photo is taken and runs to 12 seconds afterwards.
Best thing to do is to try both options and see what works best for you. Remember to set the camera from 3 shots to 1 first and make sure it's back to taking 1 shot at a time before you switch to photo + video.
You can keep an eye on how full your card is in the status report. I have an 8 G card that has been in a camera for months. It started overwriting and had overwritten the first 200 files, but it has 1980 files, so 990 pics and 990 videos.