School-Safe Puzzle Games

## Guess my age

"My wife’s age", said John, "can be found by reversing the figures of my own age. She is my senior, and the difference between our ages is 1/11 of their sum".

How old is John?

### 29 Comments to “Guess my age”

1. zxo | Profile

(W-J)*11=W+J
10W=12J
W/J=6/5

So we know that John’s age must be a multiple of 5, and that the first digit must be less than the second (because his wife is older). Thus, we are left with 15, 25, 35, and 45. Of these, only 45 fits the requirement that W/J = 6/5.

Thus, John is 45 and his wife is 54.

2. falwan | Profile

John = 45;John’ Wife = 54…

54 – 45 = 9 ;;; 1/11(54 + 45 ) = 1/11(99) = 99/11=9.

Thanks.

3. falwan | Profile

John = 45 ; John’ Wife = 54.

4. Shawn | PUZZLE GRANDMASTER | Profile

John is 45.

When you reverse ages, the difference between them will always be 9.

F = female’s age
M = male’s age
(F – M) = 9

So : (F + M) / 11 = (F – M) = 9

and : (F + M) = 99

John is 45, wife is 54

5. sharhan | Profile

The wife is 54, John is 45…quite easy.

6. suineg | PUZZLE MASTER | Profile

A=First digit of Jhon Age
B=Second digit of Jhon age

My wife age is the reverse of my digits and she is my senior:
BA>AB

the difference between our ages is 1/11 of their sum:
BA-AB= (AB+BA)/11—> 10BA/12=AB now this give you some possibilities, but the reverse of the digits gives you a hint:
there is a pattern: if the distance between A and B is 1 the difference between BA and AB is 9*1, if its 2 is 9*2 and so on, for example:
50 and 05, the distance is 5 and the difference is 9*5= 45= 50-05.
the difference has to be a multiple of 9 and AB= 10/12 BA:
the distance has to be one because the difference between BA and AB has to be 9 cant be greater because of the relation AB= 10/12BA
now you can see what number with the distance between his digits in one fufill the condition: 54—45

7. sarag | Profile

John is 45 yo,
his wife is 54 yo.

8. theWizof6 | Profile

John is 45

9. cdv02d | Profile

John is 45, making his wife 54.

10. foger1979 | Profile

he is 45
she is 54
Together they are 99
Difference is 9 or 1/11 of 99

11. pedstar | Profile

John is 45.

12. drew101010 | Profile

Johns age is 45. Wifes age is 54. The sum of them is 99 and the difference 99. 9/99 is 1/11.

13. da Moose | Profile

John is 45.

14. jasc | Profile

^ got too excited, forgot about digits

John’s 45

15. sunshine1953 | Profile

John is 45

16. mgillig | Profile

John is 45

17. doylerules | Profile

The husband is 45. The wife is 54.

The equation that you use is:

wife’s age=husband’s age*1.2

This leaves only 18 possibilities because the answer must be an integer. I brute forced it from there!

18. T | Profile

Her Age – His Age = (Her Age + His Age)/11

So testing ages for which the digits could be reversed, starting at a reasonable difference (54 and 45) you get the answers.

She is 54 he is 45.

19. GIGS1890 | Profile

Johns 54. Wife is 45.

difference of 9, sum of 99.

Got through basic Algebra (let one of the digits be a, the other b. John’s age is 10a+b, wife’s is 10b+a)

20. carlhazlewood | Profile

He’s 45.

21. RK | Profile

Very good, John is 45. Several nice explanations above.

I know many of you have been asking for some difficult math-type puzzles; in about 2-3 weeks will be able to post the 1st really hard one.