Archive for the ‘Number Theory’ Category

The Globe Balls Quiz Show

Saturday, September 16th, 2017

The host of the show, Barnstorm McDoodle, stood on an elevated podium studded with multi-colored lights. Barnstorm was wearing a jacket splattered with bright small reflectors, flashing a wide Hollywood smile under a pencil thin moustache – his thick, abundant black hair extending backwards like freshly plowed furrows in a field.

A large, transparent plastic globe full of thousands of small colored plastic balls stood in the middle of the floor between Barnstorm McDoodle and the opposing consoles of team A and B. From the globe a tube led into a small tray.

“Tonight, the contestants – Jack and Jill on my left, Mabel and Seymour on my right – can win a lot of money by guessing how many balls there are in this large globe,” announced an animated Barnstorm McDoodle, waving his arms regally to contestants and audience.

“But…if they fail…they win nothing, and the pot will be doubled for next week’s contestants,” added Barnstorm McDoodle.

“To investigate the contents of the globe, the contestants will enter numbers at their panel, to be repeated on this large screen. The number will divide all the balls in the globe into equal groups, ungrouped balls rolling out from the globe through this tube into the tray – which balls my lovely assistant Jane will fetch and replace in the globe.”

“The first team to correctly state how many balls the globe contains will win an amount in dollars equal to the number of balls,” proclaimed Barnstorm McDoodle.

“Any team can request a five minute break to work out a guess, but if it’s wrong they’ll be disqualified, so let’s get on with the show,” shouted Barnstorm McDoodle.

“But first a word from our sponsor, Ace Dogfoods.”

After Ace Dogfoods’ prolonged message, Jack and Jill entered “2” at their panel, which then appeared on the large screen. One ball rolled out into the tray and Jane stepped forth briskly on long legs to put the ball back into the globe.

“Write it all down, Jill,” said Jack.

Mabel and Seymour entered “5” and four balls rolled out into the tray, rapidly picked up and replaced by a smiling Jane.

Jack and Jill entered “6” and five balls rolled  out into the tray, Jane wiggling into action again.

“I see where this is going,” said Jack. “Let’s find a zero.”

Then, Mabel and Seymour entered an “8,” which resulted in seven balls in the tray, recovered in lithe strides by Jane.

Jack and Jill decided to take a chance and entered “11” at the panel. This time no balls came out of the globe.

“Yes!!! We request a break,” said Jack quickly, pulled out his calculator, a pen and notepad.

“Ok, folks, let’s see if Jack and Jill can guess the right number while we hear a word from our sponsor, Ace Dogfoods,” said Barnstorm McDoodle cheerfully.

“Come on Jill, use what you learned in the number theory course to figure this out rapidly before Mabel and Seymour do,” said Jack urgently. “I want to buy that motorcycle.”

“Ok, Jack, I think I see the pattern,” said Jill with a dimpled smile. “Write down what I say and get your calculator ready to win the Caribbean cruise I want.”

At the end of the five-minute word from Ace Dogfoods, Jack announced the result Jill had worked out – which, happily, turned out to be the correct number of balls in the globe.

“People, we have a winner for xxxxx dollars,” shouted Barnstorm McDoodle jubilantly, giving Jane a big hug.

What would you say was the least possible number of balls in the large globe?

The Pirate Gold

Tuesday, August 29th, 2017

A crew of pirates robbed a Spanish galleon off the coast of Crooked Island. Among the booty they found a chest full of gold coins.

The captain was killed during the battle, so to ensure a fair share the crew decided to immediately divide up the gold coins on a nearby uninhabited island before a new captain was chosen.

The 17 surviving pirates began distributing the coins into 17 piles on the beach, but three coins were left over. No agreement could be reached as to who would get the three coins, and, after a large amount of rum was consumed, fighting followed in which one of the pirates was killed.

The pirates then divided up the coins into new piles, but, alas, this time there were as much as ten coins left. With further violent discussions, more rum and fighting another pirate was killed.

The remaining crew set about to divide the gold coins of the chest into equal piles and this time they succeeded in obtaining an equal distribution, which, after opening another barrel of rum, they celebrated until they were spread about on the beach in a drunken stupor.

It turns out they had been observed by a small Dutch crew which had been marooned on the island after a terrible storm. This crew carried away the booty and sailed off while the pirates were sleeping off the rum.

Can you work out what the least number of gold coins in the treasure chest was?

The Family Ages

Monday, August 14th, 2017

Jack asked Fred “How old are your family members?”

“Ten years ago my father was twice my age and my mother’s age was a perfect number,” said Fred.

“That helps with your mother’s age, but I need more information about your father,” said Jack.

“No problem. The square of my father’s age is equal to the year he was born,” replied Fred.

“Ok, got it,” said Jack. “What about your brother and sister?”

“Ten years ago my sister Lara was the same age as my brother Nick is now. In two years my father will be half the age his father was when he died,” said Fred.

“Very interesting,” said Jack.

“My great grandfather told my father he would be reborn in a year equal to one quarter of a perfect number, which is when Nick’s turtle – that my great grandfather gave to my father newly hatched ten years before he died – will probably die,” said Fred.

“How nice, any more info?” said Jack.

“My sister Lara’s age is a divisor of the cross sum of the turtle’s present age,” said Fred.

“And what about your grandfather’s age?” asked Jack.

“When my father was born my grandfather was as old as half the sum of my mother’s age and that of my father’s ten years ago,” said Fred.

“Gee thanks, I’ll go and think about it,” said Jack and walked off.

What do you say are the ages of these family members, including the turtle.

The Army Sizes

Sunday, July 30th, 2017

The generals Chi Wong and Chow Loo were having a discussion one day on the top of a hill overlooking the plains of their respective army camps.

“My army is bigger than yours,” said general Chi Wong to general Chow Loo. “I’ll wager my best concubine on it.”

“Wager likewise accepted,” said general Chow Loo. The generals decided to verify the facts of the matter and called in their major generals Soo Flick and Boo Mung to settle the issue.

“Soo Flick, arrange my army in a square below on the plain so you can more easily determine the number of men in my army,” commanded General Chi Wong.

Major general Soo Flick ran off to comply with the order, and major general Boo Mung ran off to carry out the same command issued by general Chow Loo.

The following day the armies were arrayed in square formation on the plain below and major generals Soo Flick and Boo Mung returned to report the result.

“Honorable generals Chi Wong and Chow Loo, we have determined that general Chow Loo has 3,011 more men than there are in general Chi Wong’s army,” reported major generals Soo Flick and Boo Mung.

“What a surprise! But I’ll win Li Mai back on the next bet,” said general Chi Wong confidently.

Can you work out how many men there were in the armies of the generals?

The Backward Check

Sunday, July 30th, 2017

Albert Jones went to cash a check in a bank. The bank teller, named Bonzo Sludge, had just smoked some weed and his mental faculties were distorted leading him to wrongly read the amount written on the check, the numbers swimming around in his head and forming an amount in reverse order.

Bonzo Sludge paid Albert Jones the erroneous amount with a silly, cross-eyed grin on his face and continued playing his video game on the computer at the teller station.

After receiving the money, Albert Jones checked the amount paid out to him and noticed that money was missing and that the missing amount was a square number.

Albert Jones returned to resolve the error with bank teller Bonzo Sludge, but after receiving a vacuous, bovine and uncomprehending look Albert Jones decided to head for the bank manager’s office, where he received the missing amount of money and assurances the personnel glitch would be remedied.

Can you work out what the missing amount was?

The Pirate Tombstone

Monday, July 24th, 2017

It was a bright blue sunny Caribbean day with occasional fluffy clouds sailing by like galleons over an island with abundant jungle growth and a lively variety of bird chatter.

“Look there, Arby. Isn’t that a tombstone,” shouted Pascal, assistant to explorer Dr. Arbuthnot Smythe, as he ran to inspect a black rock hidden among foliage under some palm trees on the remote uninhabited Caribbean island Esmeralda.

“Well spotted,” Dr. Smythe followed Pascal to inspect the black rock. “Clean up the surface so we can see what’s written on it,” said Dr. Smythe, following close behind.

Pascal was already busy brushing the black rock free of debris and growth, revealing the large letters R I P with the name Jack Black Silver below.

“Could be treasure decoy work by Capt. Kidd, indicating that we are on the right track based on the parchment incrusted with an emerald and black seal we found in an old ship’s log at Boggs’ Antiquary in London,” said Dr. Smythe after examining the black tombstone.

“There is more text chiseled in under the name,” said Pascal enthusiastically. “Very strange, there are three large numbers with letters.” Pascal scratched his head with a puzzled look on his face.

“What are the numbers,” asked Dr. Smythe, standing ready with notebook and pen.

“Arby, they read as follows: 180XYZ34, 158XYZ and 982XYZ8, one number above the other,” replied a befuddled Pascal.

“I say, definitely not coordinates,” observed Dr. Arbuthnot Smythe, tapping his pen on the pad.

“Wait, I see some small writing below which reads:

By dyviding the dyvisor, ye pace 19 rest N, then pace 12 rest W.’

What in the world could all that gibberish mean?” exclaimed Pascal.

“Hmm,” said Dr. Smythe, scratching his van Dyke beard, concentrating on the numbers. “I would say we need to work out what the letters stand for. I believe Capt. Kidd’s treasure chest could be buried nearby,” said Dr. Smythe deep in thought.

“Maybe the word ‘rest’ means ‘remainder’,” commented Pascal.

“Inspired thought, Pascal, I think you are on the right track. Get your calculator out and let’s solve this riddle,” said Dr. Arbuthnot Smythe with enthusiasm.

About how many paces from the black tombstone would you say the treasure is located?

The Brimchester Football Bar

Friday, July 14th, 2017

Marco Slivovitz, owner of The Brimchester Football Bar – dedicated to all fans of the honorable soccer sport – had just installed a perfect number of spherical beer kegs, painted to resemble footballs, which were placed around a large circular bar room.

Enthusiastic  fans celebrating the most recent victory of their beloved team could freely tap and drink beer from any one of the perfect number of spherical football kegs, conveniently placed around the extensive bar area – instant payment being made by card, and large beer mugs provided by saucily dressed waitresses.

Marco had a problem.  As the bar guests would usually empty all the kegs during an evening’s merrymaking, he needed a delivery truck with the correct spherical capacity to fill his perfect number of spherical beer kegs so they would be ready for the next bout. The radius of each of his spherical beer kegs was 21 inches.

Being a practical man, he turned to the yellow pages of the phone book to check for a firm specializing in beer delivery trucks with spherical containers, keeping in harmony with his own containers.

Luckily, after a persistent search, Marcho Slivovitz found the right company for his purposes, Acme Spherical Deliveries.

After contacting Acme Spherical Deliveries and giving the friendly sales person the details regarding his spherical beer kegs, Marco was delighted to hear that two spherical delivery trucks could actually be made available on a regular basis for his purpose, however each with a different diameter.

With the situation happily resolved, being a practical man, Marco Slivovitz proceeded to have one of his waitresses help him test his spherical beer kegs for proper functionality.

 

Can you work out the radii of the spherical containers on the Acme Spherical Deliveries trucks that will  completely fill up Marco’s empty spherical beer mugs after a spirited football victory celebration?

 

The Special Number

Thursday, March 23rd, 2017

On a late June afternoon, Jill sat on the green grass by a small lake at the university with a concentrated look on her face. Some ducks were quacking nearby.

“Hi Jill, I see you are thinking about something, anything important?” said Jack, who had quietly walked up to her on the grass.

“I need a vacation and there’s this problem I’m trying to work out, Jack” said Jill in an exasperated tone of voice.

“Seems you are not progressing much. Tell me all about it,” said Jack, sitting down beside her.

“The travel magazine ‘Your Perfect Vacation’ is holding a contest where the winner will get a two week, fully paid vacation for two at a bungalow in Curacao in the Caribbean, and I want to win the prize,” she said with a determined look.

“Sounds interesting. I enjoy basking in the sun and doing some snorkeling. Want some company on the trip if I help you?” offered Jack eagerly.

“You bet, Jack. Have a look at the problem, the deadline is tomorrow.” Jill handed him the magazine, pointing to the advertisement.

Jack began reading out loud: “There is a number that starts with a digit and is followed by four digits that are the same. Square this number and subtract one to give a ten digit number, none of whose digits are the same.”

Jill was looking expectantly at him, hoping to see a light turn on in his eyes.

Jack’s face brightened up. “Jill, this is no big problem. Some number theory that I know will make it easy,” smiled Jack.

“So glad to hear it, Jack. Let’s go over to my place, work it out and enter the solution on the magazine’s webpage,“ invited Jill.

“Curacao, here we come,” said Jack, nimbly pulling Jill up on her feet.

Jack and Jill gathered their things and walked off together down a tree-lined path.

What do you figure is the number Jack and Jill are looking for?

The Square Armies

Monday, March 13th, 2017

Emperor Manos was standing outside his tent on a hill overlooking his vast army camped in tents in the square formation normally used in battle. General Pathos and a Royal Guard were with the Emperor, as was his sorcerer Morgan.

A raven briskly landed on a large branch of an oak tree. “Guard, shoot the raven, Zanora must not know of our plans,” commanded Emperor Manos.

The guard rapidly and expertly pierced the raven with an arrow, and it fell croaking from the tree striking the ground.

“Well done, guard. It was a spy bird sent by the High Priestess, Zanora, who uses its eyes and ears to observe what we are discussing so she can report it to King Kali for his attack tomorrow,” explained Emperor Manos.

“How many men are left in my army, General Pathos,” asked the Emperor.

“Lord Manos, prior to our last battle we had counted twelve million men, but sadly we lost quite a few,” replied General Pathos, eyes downcast.

“What about the number of men in King Kali’s army. What can you tell me, Morgan?” requested Emperor Manos.

“Lord Manos, my divinations have revealed a maximum of 19  million men,” replied Morgan.

“General Pathos, blow the horn for attack at dawn. When the battle starts we will see how things develop, but as the moon is full, Morgan could invoke the Moon Goddess Iona and have her conjure up 18 auxiliary units of soldiers in square formation to reinforce our army, if needed,” the Emperor informed General Pathos.

“Lord Manos, I’m glad to hear this. We will be ready at dawn for this massive and decisive battle to save our people from the evils of King Kali’s black magic,” responded General Pathos.

At dawn, Emperor Manos’ army attacks, but, after seeing the great mass of soldiers in King Kali’s army storming forward, the Emperor soon realizes that his army is greatly outnumbered.

“Your conjuring rite for the 18 units is needed, Morgan,” shouted Emperor Manos.

Morgan climbed onto a small mound and raised his hands to the Moon goddess Iona, sounding an invocation. After a short while,  eighteen units of fully-armed soldiers materialized out of a large mist just ahead of Emperor Manus’ army, nine units on either side forming a bull’s horn attack configuration.

“I have done as commanded, my Lord. The Moon Goddess Iona informs me that our army and King Kali’s are now equally matched with the same number of men,” said Morgan.

“Thank you, Morgan, you have performed an invaluable service,” exclaimed Emperor Manos

Then King Kali’s army splits up into 16 equal square units forming a semi-circle and attacking Emperor Manos’ army with great intensity.

“My Lord Manos, if I knew how many men there are in any one of the 16 units of King Kali’s army, I could create a resonance spell resulting in a multitude of ghostly apparitions that sow great confusion and disorientation among King Kali’s soldiers,” said Morgan.

“Yes, this will definitely save the day for our island Ruta,” enthused Lord Manos.

“Guard, summon Leonoros, the Court Astrologer, immediately. We need to calculate the number of men in any one of these 16 units,” shouted Lord Manos.

The guard hurried off to fetch Leonoros, the Court Astrologer.

To help Lord Manos win the battle, how many men would you say are in one of King Kali’s 16 equal units?

Can you also work out the number of men in one of the eighteen conjured units?

And while you are at it, what about the size of the opposing armies?

Farmer Couples Out Shopping

Saturday, January 28th, 2017

In a late autumn afternoon, Jill was sitting under a tree on a campus hill looking despondent,  elbows on her knees and hands holding up her head. Sunlight was fading while yellowish and brown leaves floated erratically down from trees.

Distracted, she did not notice that Jack was approaching from below.

“Hi Jill, you look unhappy,” said Jack. “Want to tell me about it?” He sat nimbly down beside her.

“I think my math professor, Mr. Torquemada, doesn’t like me,” moaned Jill. “He gave me an assignment I have to turn in tomorrow and explain in class, and I can’t figure out head or tails of the problem,” she said shaking her head with a forlorn expression on her face.

“Why don’t you explain the problem to me, maybe I can think of something,” offered Jack with a sympathetic smile, placing his hand lightly on her back.

Jill sighed deeply. “Ok, Jack, here goes:”

“Eight young couples went to the Texas Combo Farm Equipment and Livestock Market to make purchases for the farms they were establishing to form an ecological farming enclave.

The husbands’ names were Henry, Archie, Guiseppe, Pavel, Heinz, Juan, Erik and Shu Wu. The names of their wives were Elfrida, Gunnhilde, Lola, Mary, Teresa, Sally, Jasmine and Lulu.

They all bought the same number of an item as the price of the item in dollars.

It turned out that, respectively, all of the husbands spent 945 dollars more than their wives.

Guiseppe bought 35 more chickens than Lola. Pavel spent 2673 dollars more than Elfrida. Erik bought 95 more pigs than Lulu. Henry spent about one fifth as much as Heinz. Juan bought just about twice as many cows as Sally. Jasmine bought more items than any of the other wives. Mary bought thrice the number of seed bags as Lola. Erik spent about three times as much as Gunnhilde, and relatively a little bit more than Teresa.

 How much did Shu Wu spend, and what was the name of his wife?”

“What a muddle, Jill. What did you do to upset him?”

“Professor Torquemada invited me to a friendly Saturday night dance at his fraternity’s house, where he is a supervisor, and I turned him down, somewhat abruptly I’m afraid,“ explained Jill.

“Oh, I see,” replied Jack, suppressing a laugh.

“Jill, I am taking a course in computer programming and figure that this is an easy problem to solve with a few lines of code,” said Jack encouragingly.

“Please  help me with this, Jack,” pleaded Jill. “I would naturally compensate you somehow,” offering a demure smile.

“Deal,” said Jack. “Come with me. I know a place where we can write some code. I think a double loop will do the job,” he added.

“What’s a double loop?” wondered Jill.

“I’ll show you later.”

Jill jumped up, gathered her books and followed Jack down the hill.