+306 Find the number of ways of arranging the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 in a 3x4 array (with three rows and four columns), so that the sum of the numbers in each column is divisible by 3. Each number must appear exactly once in the array.
I would really appreciate some help with this problem. Thank you!!
+118673 This question has already been done to death.
https://web2.0calc.com/questions/counting-problem_8
You can continue the discussion on the original thread if you want to.
Continue on the original thread BUT you can put a link here saying you have done so. (Otherwise, your addition is likely to be overlooked)
