How many 10 mega pixel pictures will a 1 gigabyte memory card hold?

The answer to your question will depend on the type of camera, how you are storing the files and how complex the images are. In general, you should be able to get about 200-225 pictures on a 1GB memory card, assuming that you are saving the files in JPEG format. Saving in RAW format will reduce the number of pictures. Since JPEG is a compressed file format, the files will vary in size based on how complex the pictures are. So the total number of pictures that you can get on a card will vary based on how well the JPEG compression algorithm is able to compress your photos.