This is a way of determining someone’s age by a devious means, but will only work if they are willing to take part by carrying out the given set of computations, using a calculator if required.
1. Add 1 to the number of the month in which you were born.
2. Multiply by 100.
3. Add the day of the month in which you were born.
4. Multiply by 2.
5. Add 11.
6. Multiply by 5.
7. Add 50.
8. Multiply by 10.
9. Add your age.
10. Add 61.
Now ask for the resulting number and subtract 11111; the pairs of digits from the right give the person’s age, day of the month in which they were born, and birth month.
Check it out on yourself before trying it out on someone else. how does it work?
Ans. : Let m be the number of the birth month, let d be the day of the month, and a be the age. Then the steps, if carried out correctly,
compute 10000m + 100d + a + 11111.