Open Middle®
Directions: Using the digits 1 to 9, at most one time each, place a digit in each blank to create the smallest possible value for a.
Hint
What rows/columns from the first matrix impact a?
What rows/columns from the second matrix impact a?
What rows/columns from the second matrix impact a?
Answer
There are many possible solutions for digit positioning, although the pairs should be constant. 1 & 6, 2 & 5, 3 & 4. One example would be:
Source: Bryan Anderson
A variant might be to fill in the blanks to find the smallest (or largest) value of |a – b|
Nice Phil. Thanks for suggesting this. You should consider submitting it as a separate problem using the Submit link in the menu bar.
Smallest value is 0:
6 8 4 3 38
5 7 9 2 38
1
SW and ML
Kings College Alicante, Spain
Love this question. Not seeing how the answer is 0, though. All digits are positive …
I’m getting 6(1) + 5(2) + 4(3) = 28