In reply to drmarten:
Neither I nor anyone else has a universal definitive answer.
Living in Snowdonia, on the slopes of the Carneddau, the neighbouring mountains are the Glyderau and Snowdon range. Taken together, they make a challenging walk, and done in this manner, you don't really hit intervening sub 3000' peaks en route. Gets a bit silly, but you can claim Castell y Gwynt and the recently named Carnedd Gwenllian if you like.
From my Cymrucentric view of what constitutes a 3000' mountain, I thought It'd be fun to walk the other 3000' mountains of Britain. I understood there were 4 in the Lakes, and about 282 in Scotland. Made a nice round 300, and good enough for a framework to base my trip of a lifetime on.
Once I got the maps out for Scotland, however, it became apparent that, using my Welsh way of thinking about 3000' mountains there were a lot more than 282 of them. I found out about Munro Tops. But even they didn't seem to stand as equivalent to a Welsh 3000' if you claim there are fifteen of them - there would have to be yet more of them than just munros and tops.
Ultimately, it didn't really matter. I had a big walk and enjoyed myself.
When I had my first digital camera, it was 3.2 megapixels. Now my mobile phone has an 8 megapixel one.
In both cases, I've enjoyed the photo's they produced. Composition was key to that, not the number of pixels.