Discussion in 'Physics & Math' started by ProCop, Jan 8, 2005.

1. ### PeteIt's not rocket surgeryRegistered Senior Member

Messages:
10,166
Yes, I'm living in the past

3. ### SarkusHippomonstrosesquippedalo phobeValued Senior Member

Messages:
7,784
Okay - then it's 7, 10 and 28.

Sum is 45.
Product is 1960
2005 less 45 is 1960.

Messages:
10,166

7. ### geodesic"The truth shall make ye fret"Registered Senior Member

Messages:
1,002
Yep, that's what I got.

Pete:
I believe so, but I can't think of any non-exhaustive way of proving it, at least, not right now.

8. ### ProCopValued Senior Member

Messages:
1,258
Really something!!

I found this puzzle on the web and it is a topper:

Mother is 21 years older than her son.
After 6 years she will be 5 times older than the son.
Where is the father?

9. ### PeteIt's not rocket surgeryRegistered Senior Member

Messages:
10,166
Oh, that's rude!

10. ### ProCopValued Senior Member

Messages:
1,258

Accord, but let's conclude that smart thinking cannot be intimidated by supposed vulgarity of some elements of life...

Messages:
4,795
Jamaica?

Messages:
4,795
Prison?

13. ### PeteIt's not rocket surgeryRegistered Senior Member

Messages:
10,166
Well Jamaica is warm and wet... and the husband is in a warm, wet place...

14. ### tablariddimforexU2Valued Senior Member

Messages:
4,795
I guess you're assuming that the son is 'just being made' at the beginning of the puzzle, but I just can't get my head round the math to work it out.

15. ### oxymoronRegistered Senior Member

Messages:
454
Hehe! Thats a really good puzzle!

Age of son: -9/12 (assuming 9 months until conception).
Age of mother: 20.25yrs old

After 6 years...

Age of son: 5.25 years
Age of mother: 26.25

5.25x5 = 26.25

Therefore the father is in bed.

16. ### oxymoronRegistered Senior Member

Messages:
454
Alternatively if you had no idea you could do this from scratch.

The puzzle must satisfy two equations:

(1)... x + 21 = y
(2)... 5(x+6) - (y+6) = 0

(1) says that the age of the son (x) plus 21 equals the age of the mother (y). Then (2) says that the difference between 5 times the age of the son plus 6 and the age of the mother plus 6 is zero.

So we have

(1)... x - y + 21 = 0
(2)... 5x + 30 - y - 6 = 0

=>

(1)... 5x - 5y + 105 = 0
(2)... 5x - y + 24 =0

Solving simultaneously...(1)-(2)...

-4y +81 = 0
y = -81/-4 = 20.25

Substituting back into (1) we have

x - (20.25) + 21 = 0
x + 0.75 = 0
x = -0.75

Hence the age of the mother is 20.25 years and the age of the son is -0.75 years or -9 months. And you can assume whatever you want from there.

17. ### ProCopValued Senior Member

Messages:
1,258
This is the answer the Parent Control application on my PC would allow to show on the screen and it is not neccesary to specify the exact position/placing of the involved organ of paps in the vicinity of mams physionomy to solve the riddle.

18. ### oxymoronRegistered Senior Member

Messages:
454
restrain? what restrain?

Sorry ProCop, I simply had to answer it - it was such a cool puzzle. I liked how one of the ages was actually negative which really gets you thinking!!

19. ### ProCopValued Senior Member

Messages:
1,258
@Oxymoron

Your answer is corect, thanks for the work out maths. When I first saw the riddle I thought that it was one of those stupid trying-to mislead-you puzzles, but it turned out to be a very clever one...

20. ### ProCopValued Senior Member

Messages:
1,258
Got this one in a mailgroup..(very witty)

When the old rancher died, and left the ranch to his
three boys, their mother suggested a new name for the ranch.

"Focus"

Where the sons raise meat.

Why "Focus" ?

21. ### §outh§taris feeling causticRegistered Senior Member

Messages:
4,832
The hostess at her 20th wedding anniversary party tells you that the
youngest of her three children likes her to pose this problem, and proceeds
to explain: “I normally ask guests to determine the ages of my three children,
given the sum and product of their ages. Since Smith missed the
problem tonight and Jones missed it at the party two years ago, I’ll let you
off the hook.” Your response is “No need to tell me more, their ages are : : : ”

22. ### §outh§taris feeling causticRegistered Senior Member

Messages:
4,832
You are told that the three numbers are primes and that they form the sides
of a triangle with prime perimeter. You see 5 and 7 on the other two people,
both of whom state that they cannot deduce the number on their own

--
Same source as the other.

23. ### RosnetPhilomorpherRegistered Senior Member

Messages:
681
11
5+7=12
Next prime numbers: 13, 17, 19, 23, 29,... (Perimeters)
Third side, possibly: (Perimeter-Sum of two sides).
13-2=1; 1 is not prime.