+-----------------+
|1 + 1 + 1 + 1 + 1|
|1 + 1 + 1 + 1 + 1|
|1 + 1x0 + 1 = ?  |
+-----------------+

Consider the abovementioned addition and multiplication problem.

Determine the number that will replace the mark of interrogation, given that it is NOT 12.

Notes:

1. All the calculations are in the decimal (base 10) system. Calculations done in non-decimal system is NOT permissible.
2. Although this puzzle is in "tricks" category, some amount of logical thinking must be enunciated while solving this problem.

Perhaps we could ignore the usual order of operations and just work left to right and top down.  

Posted by Jer on 2023-01-02 16:24:33