This Tricky Maths Puzzle Shows How Imperfect the Human Brain Can Be

Here’s the problem again.

If you saw all the number ones, you may have assumed that there was an invisible plus sign at the end of the first two rows. The fact is, there are no plus signs at the ends of the rows. What that means is that these are 11s, not ones. Therefore, the solution to this problem is 30.

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