The number of photos printed is a hard number to come by as each photo has different aspect associated with it. Most of all determined by the color spectrum of the shot. the extreme example would be a black and white image, this would take no color ink [printer set to grayscale so that color ink isn't use] would print many more photos than printing color images. You can see than that the color spectrum of the image is a factor in how much ink is used. Also the size of the image is a contributor in determining the number of images printed.