2) 4×4
Every row and column adds up to 50

3) 5×5
Every row and column adds up to 100.

This type of puzzle was published in Cijfervaria, a publication of Sanders Puzzelboeken. As I write this, they just published issue 5. Though I missed issue 4, I see they regularly publish Soduko variants, Binairo, Triairo, hitori, and battle ship.

You can check your solution here, here and
here.

Did you know…
Learning new tasks saves brain cells – even if these tasks are more or less similar to already known tasks.