Question 19
Four cars $A,B,C,D$ race from São Paulo to Fortaleza, starting in the order $A$, then $B$, then $C$, then $D$. During the race, $A$ and $B$ exchanged positions (overtook each other) 9 times, and $B$ and $C$ exchanged positions 8 times.
To determine the finishing order in Fortaleza, you may only ask questions of the form:
“How many times did cars $X$ and $Y$ exchange positions?”
Before asking the next question, you know the answer to the previous one. Formulate three questions that determine the finishing order of all four cars.
To determine the finishing order in Fortaleza, you may only ask questions of the form:
“How many times did cars $X$ and $Y$ exchange positions?”
Before asking the next question, you know the answer to the previous one. Formulate three questions that determine the finishing order of all four cars.