C (4,2) = 6 (species).

Therefore, two customers choose gifts in the following way.

6×6=36 (species)

Consider that two customers choose exactly one gift, and there are several possible choices.

First of all, there are four ways to choose the same gift; Then two customers choose two different gifts from the other three, and the choices are as follows.

A (3,2) = 6 (species)

Therefore, among the gifts chosen by two customers, there is just one possible choice.

4×6=24 (species)

So the possibility is

24/36=2/3

Because it is three independent repeated events, the probability of each start is1/a (10,3) =1/720.

The probability of three times is 3x 1/720= 1/240.