android - How are bitmaps scaled? -

i have 2 bitmaps. bitmap 257x257, , bitmap b 255x255. container both being placed in 256x256. how bitmaps scaled? in other words:

1) how can bitmap scaled small values, such 1 pixel?

2) difference between scaling bitmap (placing b in container) , scaling bitmap down (placing in container)?

3) there difference in cost between scaling in either direction 1 pixel vs 100 pixels?