Wednesday, April 27, 2011

It's Not About Math

two men meet on the street. they haven't seen each other for many years. they talk about various things, and then after some time one of them says:

"since you're a professor in mathematics,
I'd like to give you a problem to solve....

the mathematician: "what problem?"

the father: "you know, today's a very special day for me
all three of my sons celebrate their birthday this very day!
so, can you tell me how old each of them is?"

"sure" answers the mathematician, "but you'll have to tell me something
about them"

"OK, I'll give you some hints" replies the father of the three sons , "the
product of the ages of my sons is 36"

"that's fine" says the mathematician, "but I'll need more than just this"

"the sum of their ages is equal to the number of windows in that building"
says the father pointing at a structure next to them

the mathematician thinks for some time and replies: "still, I need an additional
hint to solve your puzzle"

"my oldest son has blue eyes" says the other man.

"oh, this is sufficient!" exclaims the mathematician, and he gives the father
the correct answer: the ages of his three sons

the answer is simple: "It's Not About Math"

the possible combinations: "from the 1st point"
1 + 1 + 36 = 38
1 + 2 + 18 = 21
1 + 3 + 12 = 16
1 + 4 + 9 = 14
1 + 6 + 6 = 13
2 + 2 + 9 = 13
2 + 3 + 6 = 11
3 + 3 + 4 = 10

unfortunately the 2nd point is distracting... the number of windows was 13

then comes the 3rd point:
my oldest son has blue eyes
no, no, wait... it's:
my oldest son has blue eyes

the ages of the three sons must be 2, 2, 9

if we can really understand the problem, the answer will come out of it; because the answer is not separate from the problem

source: How to Solve It: Modern Heuristics


  1. I did not get this solution ,why the numbers (1,1,38),(1,2,18),(1,3,12),(1,4,9),(2,3,6),and(3,3,4) is not a possible solutions.

  2. The number of windows wasn't sufficient, so the only possible solution is the repeated one which is 13. the other possibilities have a unique sum

  3. I am not 100% sure either, but I believe its because you have to break the 2nd clue to two bits.

    (The sum of their ages is equal) to the number of windows in that building.

  4. i did not know why the numbers(2,2,9) but not the numbers(1,6,6).... and,, what is the relathion between the (blue eyes) and the number (9)