Ugh, you're all over the place in your posts. You could have the correct idea, and just be expressing it poorly, or you could have the incorrect idea. In any case, I will spell it out more clearly.
If you are training one position training (as it sounds like you are doing), you should be able to train 2.5 people per week. Your two main trainees should get just a little bit more than 48 minutes, and the third trainee should get the rest. If you can get them all 48 exact, more power to you. This is all that matters for the purposes of getting trained, the number of minutes they got at the position being trained.
However, game shape is another important consideration you want to pay attention to. This depends on a players minutes at all positions. This should be somewhere between 45 and 75 (55-60 is best). So if you get your trainees to 48 minutes each from the first two games in the week, you don't really need to get them many minutes to ensure proper game shape.