george357 said: \(\displaystyle \frac{13}{30}\frac{12}{30}\) Both are the same but yours the names were known! [/QUOTEIf both are the same why didn't you get the same answer??????? So what would he probability be if I switch the their names? That is, what is the probability that Jack will arrive between 1 PM and 1:12 PM and Jane between 1:17 PM and 1:30? Click to expand...