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 4 of 4: Identify the surviving order
DAandCBDA and CB
Detailed analysis

The order EDACBEDACB contains the two disjoint predicted pairs DADA and CBCB consecutively. It therefore satisfies the final condition, so the actual order is EDACB\boxed{EDACB}.