( 1)

The speed of the bus is 100 km per hour.

(V-4)x6/60=(V+4)x(30/7)/60

7V-28=5V+20

2V=48

V=24 (km/h)

So the distance between the bus and Xiao Ming is different:

S = (24-4) X6 =120km.

So the departure time interval is 120/24=5 minutes.

(2) The tutor's work efficiency is X,

Then the efficiency ratio of guidance is 5: 3,

The efficiency of getting an apprentice is 3/5 X.

The Lord always * * * handles 2X.

Apprentices always handle 6/5X+240.

Master and apprentice are always dealt with (2X+6/5X+240).

2X =(2X+6/5X+240)*3/8-40

The solution is X=62.5.

So there are * * * copies (2*62.5+6/5*62.5+240)=440 copies.