A * * * arrangement method is 6! . There are two kinds of probability that there is at most one cultural lesson between two adjacent cultural lessons: 1, and there is no art lesson between each cultural lesson; 2. Every culture class is separated by an art class.
The first probability is: 2*3! *3! The second probability is 3! *4*3*2
So the probability is (2*3! *3! +3! *4*3*2)÷6! = 1 1/30