1, let a = {circle throws into the box} and b = {circle throws out the box}
Note that P(A)+ P(B)= 1.
P(A) and P(B) are set by themselves or pass the test frequency estimation.
2. Let c = {point J in the trap} J = 1, 2, 3, 4, 5, 6, 7, 8, 9.
Pay attention to ∑ p (c) < 1, because a circle falling into a square does not necessarily trap items.
The values of P(C) and j, that is, the values related to the position of the article, should be the largest.
The size of P(C) can be estimated by experiments or set theoretically, which is related to the distance and angle of people.