18.12.9.6.24.27.3.9.21 fill in the nine spaces of the square so that the number of three in each row equals 43

18.12.9.6.24.27.3.9.21 fill in the nine spaces of the square so that the number of three in each row equals 43

It's impossible because 43 is not a multiple of 3. 18.12.9.6.24.27.3.9.21 is a multiple of 3