An Arab sheikh tells his two sons to race their camels to a distant city to see who will inherit his fortune. The one whose camel is slower will win. The brothers, after wandering aimlessly for days, ask a wise man for advise. After hearing the advice they jump on the camels and race as fast as they can to the city. What did the wise man say?
Each son owns a camel, let’s call them Camel A and Camel B. If Camel A is slower, son A gets the fortune. If Camel B is slower, son B gets the fortune. Neither of the sons want to enter the city first because they won’t get the fortune.
When they switch camels, son A is now riding his brother’s camel (camel B) and son B is riding his brother’s camel (camel A). Now, they each want the camel they’re riding to get to the city first. If son A wins the race on camel B, that means his camel, camel A, was slower and he wins the fortune. The same is true for the other way around if the second son wins the race on camel A.