This is for people who enjoy parlor games and want to find out the age of a friend or relative who is not forthcoming with the information.

Ask that person to multiply the first number of his or her age by 5  then add 3.

Next, double this figure.

Then, he or she should add the second number of his age and tell you what the final figure is.

Deduct 6, and you will have it.

-- Debra (amazeyour@friends.com), July 12, 2000

Answers

What I'd like to know, is exactly why this equations work.

Hmmm....

-- Not now, not like this (AgentSmith0110@aol.com), July 12, 2000.

Not Now,

I want to know the same thing but my head is still spinning trying to get the 12 cannonballs done in 3 weighings!! LOL

-- Debra (amazeyour@friends.com), July 12, 2000.

The key is in the multiplication. Notice the two instructions:

Ask that person to multiply the first number of his or her age by 5 then add 3

and

Next, double this figure.

So, let's say the first digit in your age is x. Then you have

((5x)+3)*2

But you can also write it as...

(5x*2) + (3*2) = 10x + 6

Starting to look familiar? All you're really doing is taking the first digit in your age and multiplying by 10, which puts the first digit where it belongs in your age. Then you add 6 (really just 3, which you then doubled) to help confuse the reader and then just subtract the 6 back out at the end.

You can actually use other numbers with this problem instead of adding three and subtracting six, as long as you keep the multiplications by five and two.

For example, you can say "multiply by 5 and add 4 (instead of 3)" and then at the end "subtract 8 (instead of 6)" and you'll end up with the same result.

-- (hmm@hmm.hmm), July 12, 2000.

hmmm: you just made me go "hmm" Thanks for the explaination!

Deb: I'm still trying to figure out the cannon ball thing myself. I've never been all that good at puzzles like that...ugh!

Mar

-- Not now, not like this (AgentSmith0110@aol.com), July 12, 2000.

good job hmmmmm, you passed the algebra exam with flying colors...

-- FactFinder (FactFinder@bzn.com), July 12, 2000.