Ken's blog

Abdullah was sitting in the shade of a palm tree in a desert oasis, desperate and worn out after walking over sand dunes the whole day since his camel had died from drinking poisoned water. Abdullah had reluctantly been on his way to meet his future bride Fatima, selected for him by his family.

A long caravan headed by five gilded camels slowly marched into the oasis and stopped near Abdullah. An ornately-dressed man with a curved sword walked up to him.

“I am Sheikh Mohammed Abu Mustafa on the way to Sebha. Why are you sitting here alone under a palm tree, my son? asked the Sheikh.

“I am Abdullah, honorable Sheikh, my camel died from drinking poisoned water so I am stranded here. I am on my way to Sebha to meet my betrothed Fatima, but as I should have been there today, she may pass on to my cousin Ali ben Daba,” he moaned.

“No matter,” said Sheikh Mohammed Abu Mustafa. “You look like a bright young man. If you can solve my riddle, you will have the hand of my lovely daughter Shahrazad. But if you fail, you will marry my mother-in-law Zaynab,” indicating a woman on one of the rear camels, a sudden wind revealing a toothless smile beneath her veil.

Abdullah was struck with fear, but soon brightened at the prospect of Shahrazad, especially since he had heard that Fatima was fat.

“Honorable Sheikh Mohammed Abu Mustafa, I will be happy to hear your riddle,” said Abdullah, knees trembling.

“Brave young man. Listen well, my son, here is the riddle.”

“The five gilded camels you see all carry bags of precious stones, each a fixed number of bags more than the previous camel. In total there are 120 bags of precious stones. Seven times the sum of the number of bags on the two rearmost equals the sum of the number of bags on the three foremost. Now, Abdullah, can you tell me how many bags of precious stones the first camel carries?” Sheikh Mohammed Abu Mustafa fixed Abdullah with a penetrating gaze.

Abdullah bowed deeply to the Sheikh, picked up a stick from the ground and made an invocatory figure in the sand. A cloud with a jinn materialized for Abdullah, but was invisible to the others. It was his family jinn who would help him.

After some moments with the jinn, Abdullah smiled and gave the answer to Sheikh Mohammed Abu Mustafa, who confirmed that the answer was correct.

“My beautiful daughter Shahrazad is yours,” said the Sheikh bidding her to present herself. “She will ride on the third gilded camel just behind you.”

After thanking his family jinn and taking his leave, a joyful Abdullah boarded the second gilded camel assigned him by Sheikh Mohammed Abu Mustafa, joining the caravan which rode off and disappeared over distant sand dunes.

How many bags of precious stones would you say the rearmost of the five gilded camels carried, and what would you say was the differential number of bags of precious stones each camel carried with respect to the previous camel?