Name: Vanessa

Level: Secondary

Question: I have a math puzzle. I have been working on it for over 2 weeks. Here it is: use the numbers 1-25 each only once. The rows across are an equation and the columns down are an equation. There are 25 boxes. You have to use the order of operation x and / first then = and -. Some of the answers are -numbers.

89 -55 -116 34 256 126 131 -130 192 49 n x n - n - n + n = x - - - + n - n x n + n / n = + + x + + n - n x n - n - n = / x - + + n + n + n - n / n = + + - x + n + n x n + n + n = = = = = =

b= Blank These were black squares on the puzzle.

The rows and columns have to equal the answer across and down. I tried to do the -numbers first. I then tries to work backwards from the answer. I tried factoring the number and using the answers. I got 7 of the equations done and the remainng numbers wont work. I would apreciate any help I can get. All this work for 10 POINTS. I would rather write a paper on a great mathamatician.

Thanks
Vanessa

Hi Vanessa,

We would also rather write a paper on a great mathematician. There seems to be no way to get around checking zillions of possibilities.

On the other hand, puzzles like that one are easy to invent: Just write down the numbers from 1 to 25 in a table in any order:

 7 23 18 9 25 8 11 6 3 17 4 19 20 10 14 15 13 2 16 22 5 1 21 24 12

Then put in division signs first, where they fit, and fill up the rest with other operations:

 7 + 23 - 18 / 9 + 25 - x / x + 8 + 11 x 6 + 3 - 17 / - - + x 4 x 19 + 20 / 10 + 14 + - + x - 15 - 13 + 2 x 16 - 22 x / x - - 5 x 1 + 21 - 24 / 12

Then solve the operations on rows and columns and hide the numbers:

53 60 64 22 24 80 221 25 163 229 7 + 23 - 18 / 9 + 25 = - x / x + 8 + 11 x 6 + 3 - 17 = / - - + x 4 x 19 + 20 / 10 + 14 = + - + x - 15 - 13 + 2 x 16 - 22 = x / x - - 5 x 1 + 21 - 24 / 12 = = = = = =

Voila! you have a puzzle as tough as the previous one, and you can throw it back at whoever assigned that monstrosity.

Claude
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