Thread: 2011: Countdown Type Puzzle

Hi, I'm a newbie and signed up to see if any of you maths wizards can help me with a quiz I'm writing up for next year.

I have several questions with numbers in the answer (actual questions unimportant) and I'd like the participants to add, subtract, multiply or divide the answers to get the number 2011 (the year AND a Prime Number!)

The numbers are:

80 - 4 - 1972 - 869 - 12 - 5

So for the answer to be 2011 using all the numbers once what should the operators be? (the numbers can be rearranged).

Is there an answer possible? Is there a web-app I could use? - I tried the Countdown calculator but it won't let me enter a 4 digit number for the answer.

Any help would be appreciated, ta!

Originally Posted by user5850040

Hi, I'm a newbie and signed up to see if any of you maths wizards can help me with a quiz I'm writing up for next year.

I have several questions with numbers in the answer (actual questions unimportant) and I'd like the participants to add, subtract, multiply or divide the answers to get the number 2011 (the year AND a Prime Number!)

The numbers are:

80 - 4 - 1972 - 869 - 12 - 5

So for the answer to be 2011 using all the numbers once what should the operators be? (the numbers can be rearranged).

Is there an answer possible? Is there a web-app I could use? - I tried the Countdown calculator but it won't let me enter a 4 digit number for the answer.

Any help would be appreciated, ta!

Since you don't know if a solution exists, my approach would be to write a brute force computer program. This means you would try every possible way to combine using the rules you stated. It would go quite fast for 6 numbers and four operations. Possibly the easiest way would be to use RPN (reverse Polish notation). I have solved a similar problem a while ago (without RPN, so the code is probably ugly) and if time allows might go back and adapt it for this one.