; A4 > a3, a5, ∴a2 can only be 3, 4, 5.

(1) If a2=3, then a4=5, a5=4, a 1 and a3 are 1 or 2, then * * has A22=2 qualified five digits.

(2) If a2=4, a4=5, a 1, a3, a5 can be 1, 2,3, * * has the qualified five digits of A33=6.

(3) If a2=5 and a4=3 or 4, they are the same as (1)(2) respectively.

∴ The five digits that meet the conditions are 2(A22+A33)= 16.

Have 1, 2, 3, 4, 5, have 1×2×3×4×5= 120.

∴ The probability of waveform number is

2

15

.

So the answer is:

2

15

.