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Mathematical fire control
According to the arrangement of tools ***A44=24, arrange all other four uses. Choose a tool that is connected correctly (there are four choices), and then the remaining tools are not connected correctly in both cases, so a tool is 4*2=8 kinds, so the probability is 8/24= 1/3.

Similarly, two pairs are 6* 1=6 species, and the probability is 1/4.

Even three must be even four, so the probability of only four is 5/ 12.

Distribute the list, you should be able to.