MathLabs

Problem 6

Five students, A,B,C,D,EA,B,C,D,E, took part in a contest. One prediction was the order ABCDEABCDE. No contestant finished in the predicted position, and no two contestants predicted consecutively actually did so. A second prediction was DAECBDAECB. Exactly two contestants finished in their predicted positions, and two disjoint pairs predicted consecutively actually did so. Determine the actual order.
Step 3 of 4: Test the consecutive pairs
AEAE
Detailed analysis

For CAEBDCAEBD and DCAEBDCAEB, the only correctly predicted consecutive pair from DAECBDAECB is AEAE. For DCEBADCEBA, none of the predicted consecutive pairs is realized. Thus none has two disjoint pairs.