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I really need help with understanding the last rule. I wrote it as [OJ] which means "O" is immediately before "J". The reason I wrote it out this way is because the last rule states that at least one of "O's" laps must be before "J". The way the game is setup it leads me to believe that if one of O's laps are before J than all of O's laps are before J. Which means "J" can never swim first. This rule has caused me to miss #23, I put "A" when supposedly the answer is "B".

Any help would be appriciated

Here's a diagram. My colleague wrote that rule as "At least once, OJ (could be in normal order or could be in the 5/6 slots)"

thx alot. the labs 1-6 5-10 are the key