1. First of all, consider 4 adults and 5 children as a whole, and these two whole groups can be arranged, that is, 2! Then four adults can also change seats with each other, so four adults should also be full, that is, four! By analogy, the children are all arranged for five!

The final formula is: 2! *4! *5! =2* 1*4*3*2* 1*5*4*3*2* 1=5760

2. This problem is to take four adults as a whole and arrange them with five children, that is, six! Then, four adults can also exchange seats, full, that is, four!

The formula is: 6! *4! =6*5*4*3*2* 1*4*3*2* 1= 17280

This kind of topic is exactly the same as the layout of our high school, but it is in English. The topic is to let these people shoot in one line. The landlord said that the line was horizontal, vertical, left and right, but it was just a question of the direction of the line. The people on the left and right are still the same. According to this statement, you can tilt 30 degrees, 15 degrees, and 45 degrees will be endless ~