Two numbers in one?

Question

I want to write two "3-digit" numbers as one "3-digit number" and be able to sort both original 3-digit numbers out later too.

For example: 222+152=374. Now, once I get 374, is there ANY way to determine that 374 came up by adding the values 222 and 152?

Its not a problem if the final number (374 here) increases to anything betweeb 0 and 999, but it should be a 3-digit number as well.

Any help greatly appreciated. Thanks.

Answer 1

If it is just the sum of two random numbers, there is not. However, you can create a set of conditions that allow you to do that. You would do it with a system of equations.

For example, if the number have to add to 374 and you have to subtract to get 70, then you can say.

X + Y = 374
X - Y = 70

You can use any of a about 5 or 6 different methods to solve the system and get the original two numbers.

Answer 2

No, there is not.

For your example, 374 = 200 + 174 = 100 + 274 = any number of combinations of 2 3-digit numbers.

To take two 3-digit numbers and combine them in such a way that, given the result, you can uniquely get back the original two digit numbers, you would have to find a "one to one function" of two variables.

Answer 3

You can work out why this is impossible.

There are (900 * 900 / 2) = 405,000 possible pairs of 3-digit numbers, and nearly half of those pairs have a 3-digit sum. There are not enough other 3-digit numbers to have a different one for each pair that you might have started with.

Answer 4

there is no way you can find out what numbers added up to the given 3 digit number

Answer 5

Nope! That's a really bad question, I hope that wasn't a question from our education system.