# Input (m,n) output...

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• Feb 23rd 2009, 01:15 PM
xx.Life.xx
Input (m,n) output...
Starting with the input (m,n), Machine A gives the output (n,m)
Starting with the input (m,n), Machine B gives the output (m+3n,n)
Starting with the input (m,n), Machine C gives the output (m-2n,n)
Starting with the pair (0,1) which of the following is impossible to obtain after using the machines any number of times ?

A. (2009,1016)
B. (2009,1004)
C. (2009,1002)
D. (2009,1008)
E. (2009,1032)

Thank you in advance
• Feb 23rd 2009, 11:01 PM
aidan
None are possible as stated.
Machine A (0,1) will always yield (1,0).
If you entered (0,1) several million times you expect (1,0) to result.

Do you intend for the output of machine A to be the input for machine B?
Machine B output to be the input for machine C & machine C output to be the input for A?

Or
Is the output of machine A supposed to be the input for the next cycle of machine A?

It is not clear.

Actually, it looks like a trick question.
• Feb 24th 2009, 12:25 PM
xx.Life.xx
So for example with (0,1) I use machine B

(0,1)
= (3,1)

Then I use machine A

(3,1) becomes (1,3).