Working out your age by beer mathematics

[lilsecret]

1. First of all, pick the number of times a week that you would like to have a beer (more than once but less than 10).
2. Multiply this number by 2.
3. Add 5.
4. Multiply it by 50 - I'll wait while you get the calculator.
5. If you have already had your birthday this year add 1760.
If you haven't, add 1759.
6. Now subtract the four digit year that you were born.
You should have a three digit number.
The first digit of this was your original number (ie how many times you want to have beer each week).
The next two numbers are your age!
(Oh YES, it is!)

[Buenchico]

I've just checked that algebraically and, yes, it will always work (unless you're a centenarian!) .

When I was teaching maths I used to love astounding my class with things like that (but, of course, without the references to booze!)

[society]

Wow! Spooky, and accurate.

[society]

Thanks for sharing this. I'm sending it to all my friends.

[mazie]

how does that work?

[ChuckFickens]

I like stuff like that too and am also (like Chris) sad enough to work it through. it works as long as you are not really old or a total alcoholic.

[mazie]

LOL...well I'm both :o(

[mazie]

I just dont like beer !

[scotman]

The number you think of initially is X
so you have

Step 1 = 2X
Step 2 = 2X + 5
Step 3 = (2X + 5) x 50 = 100X + 250
Step 4 = Add either 1759 or 1760 = 100X + either 2009 or 2010
Step 5 = subtract year of birth

Since you have a 3-digit number remaining with 100X as the leftmost digit and this year minus year of birth (your age) as the other two.

[Buenchico]

I was hoping that you'd not ask that, Mazie!

OK, here goes: Let's assume that the number of times I fancy a beer is x

Doubling it gives 2x

Adding 5 gives 2x + 5

Multiplying by 50 gives 100x + 250

Adding 1760 (for those who've already had a birthday) gives 100x +2010

Taking the age you were born from the current year (2010) reveals your age at the end of the expression. e.g. if I take 1953 away, the expression becomes 100x + 57 (where 57 is my age).

Whatever the number I started with (e.g. x =3) it will now be 100 times as big (e,g. 100x =300) at the beginning of the expression. So the first digit is now that number and the last two digits are my age.

[society]

Do you have any more tricks like this up your sleeves, Lil? Share them.:-)

[Buenchico]

I see that Scotman can type faster than me but it's good to see that someone still remembers their school mathematics!

[mazie]

Being a total dummy when it comes to Maths, I thank you both.....It was still a bit of a Whoosh moment for me. Thank you again though for taking the trouble xxx

[scotman]

Much good it does me these days

[Meg]

Blimey!!!

[mazie]

Why scotman ?

[mazie]

You really impressed me and I'm not easily impressed x

[marval]

Oh dear it works, fancy thaat

[lilsecret]

Interestingly, it will only work in the year 2010

[mazie]

Does that mean that you can pose the same puzzle with different numbers in the equation for say 2011 ?

[society]

"Interestingly, it will only work in the year 2010"

No, it doesn't...