In the case of 1 and 1 1 layer, assuming that there are m copies of the book * * and X copies are put on the first layer, then M= 1 1X+55.

2, put 7 floors, put Y on the first floor, then M=7Y-2 1.

3. There are more than 100 books in total, that is to say, the number of m is between 100-200, which conforms to the above formula 1-2, that is,1x-7y+76 = 0.

4. Manual calculation is also acceptable, or the values between m, x, Y X and y can be listed by formulas. Only M = 154, X = 9 and Y = 25 can meet the requirements, so the difference between the first layer of the two arrangements is 25-9= 16.