A Story of a “Fisherman” Looking for Young Princess Charming

By Dr. Lim Ju Boo    13^th March, 2021

(This mathematical dilemma is dedicated to Senior Civil Engineer Ir. Tan Seng Khoon, who was once the Secretary of the Astronomical Society of Malaysia)

Dear Ir. Tan Seng Khoon,

Thank you for your question below you sent to everybody for me to answer in the Year of the Ox through a chat group:  

“Ju Boo, Everybody knows you are an expert in Maths. Hope you can help out with this very difficult Maths problem here:

Math problem of the day

If George is 73 and his girlfriend is 26, how much money does George have?”

First of all dear Ir. Tan SK, I am neither  a mathematician nor a magician to know how much George has. I wish I was. Even a magician or a soothsayer would not be able to figure it out.

I did study mathematics as one of my many university undergraduate courses but that does not mean I am good in mathematics or a mathematician.

The only mathematics I know was to apply it in statistics for medical research during my previous work as a medical researcher, and currently in astronomy and astrophysics for my hobby.

In any case, no mathematician can figure out how much George has by merely you giving his age and the age of this much younger woman.

What mathematicians normally can do is to conjure up a scenario and work out an equation for an event? But even an equation or a formula would be useless without any data to substitute into an equation.

But since you expect an answer from me for this riddle, I need to find some way that can fit into the picture about this George seeing him at 73 going with a young woman at 26?

Without giving me any further details or data except a picture, the best I can do is to cook up a story about this fellow whom I believe was an American or belongs to the Caucasian race.

In order to find out how much he has, we need to do some financial calculations.

We shall not use our Malaysian currency to determine how much George has, but use their American dollar to calculate. Let us imagine this scenario.

When George came to age at 21 he does not want to go out to work. He has no interest in earning a living of his own, and he refused to do so.

He lived, ate, slept and literally thrived on his very rich uncle. He lived in his uncle’s house in the 1940’s assuming we are now in 2021.

George’s only aim in life was to be a Romeo, goes out gallivanting in search of girls and lavishly spending on them.

He used his uncle’s house as a shelter for eating, sleeping and doing nothing else.

His uncle of course was very angry with him, and asked him go out to find a job instead of remaining in his house doing nothing, but just eating, sleeping and depending on him for money to chase after girls.

His uncle refused to feed him anymore.

His uncle told him an old Chinese saying that if you give a man a fish and you feed him for a day, but if you teach a man to fish, you feed him for a lifetime.

So his uncle invested on him $100 000 and told him to go and buy a fishing boat and learn how to catch fish for a living.

But this chap George is not interested in catching fish for a living. Neither is he interested in any other job, married and brought up a family. All he was interested was chasing after young girls to be a fisher of women.

So what he did was, he took his uncle’s money and deposited it in the bank at 5 % per annum to lay eggs. He kept the money there for investment for 52 years till he was 73 so that at old age he could use the investment to chase after younger and younger girls.

At last he found this 26 years old girl in the picture.  By then he was already a millionaire.

But how much did George get out of the bank using his uncle’s money which was actually meant for him to buy a fishing boat to catch fish, not to catch girls.

Well dear Seng Khoon since you trust my mathematics, George would have got from the bank through compound interest using this formula:

P (1 + r/n)^(nt) 

= 100,000 (1 + 0.05/12)^(12x52) = $ 1,339,120.75 

This amount he got was 1,339,120.75 – 360,000 = $ 979,120.75 more than what he would got by simple interest over his 52 years of investment.

Where P is the initial principal balance, r is the interest rate, n is the number of times interest is compounded per time period and t is the number of time periods.

Wow! At 73 George was a millionaire without needing to catch fish, which he thought was sufficient to catch this 26 year old girl.

But this new 26 year old girl friend told him he needed more than just $ 1,339,120.75 because of their age difference.

So his girl friend calculated out for him how much more she needed.

His girl friend gave him this formula:

Deposit x (Age Difference) = $ 1,339,120.75 x (73 – 26) = $ 62,938,675.25

So he needed to dig out another $ $ 62,938,675.25 if George wanted to keep and maintain her.

That “maintenance allowance” was during his uncle’s time in 1948, 52 years ago when George was 21. We are already in 2021, the Year of the hard working Ox.

So he decided to throw away this girl as she demanded too much beyond his means. 

George then decided to find another even younger 18 year old girl.

So he did find a younger one. But this younger girl through Charles Darwin Natural Selection for the survival of the fittest or through social evolution of the human race - since time has change due to social needs, she demanded a new formula which he gave to George:  

Deposit x (Age Difference)^2 + simple interest of deposit

The simple interest is calculated using A = P (1 + rt), where A, is total amount needed, P is George entire fixed deposit, r the interest rate at 5 % over t = 10 years.

This means George needs to dig up more money by waiting for the girl for another 10 years, and the bank to give him just a simple interest plus his original amount.

This works out to be:  

$ 1,339,120.75 x (73 -18)^2 + $ 1,339,120.75 (1 + 0.05 x 10 years) =

$ 1,339,120.75 x 55^2 + $ 1,339,120.75 (1+ 0.05x10)

4050840269 + 1339120.75 x 1.5 = $ 4,052,848,950

This means George has to find another $ 4,051,509,829

By then George was already 83 and the 18 year old girl got married to a brilliant young 21 year old engineer, the same age as when George started his “fisher of women mission” but now without any fish to catch, sell or rear, or any family of his own to bring-up.

He started off with $100,000, but now needed another $ 4,051,509,829.

Just too bad!

Of course his uncle already passed away, and was unable to help with his “fishing investment” anymore.

So sad!

I hope dear Ir. SK Tan I am able to satisfy you with my mathematical story.

If you are not satisfied, I need to refer you to my Grand Master Sifu Ir. Lau Tai Onn to advise me on how to deal with your mathematical problem.

He is my Grand Master Sifu, and Adviser-in-Chief, as he has the last say.

Thank you. Have a nice day! 

 

Lim ju-boo