Question

The diagram below represents black and white floor tiles at a size of five by five. If you add to this pattern to make it six by six, how many black tiles would you add to the existing pattern?
I don't know how to solve it, at first I guessed 12 black tiles but it said it was wrong.

Answer 1

We can't see what the pattern is.

Answer 2

Try 11.

Answer 3

5 black tiles