I am stumped on this puzzle:
How many 3x1 pieces can fit on 8x8 board without overlapping?

Since $\frac{64}{3} = 21.\overline3$, the answer may be $21$, but no matter how I place and arrange 3x1 pieces, I cannot fit 21th piece.

So is it really $20$? If so, what do I need to know to be able to show that?

Question

I am stumped on this puzzle: 
How many 3x1 pieces can fit on 8x8 board without overlapping?

Since $\frac{64}{3} = 21.\overline3$, the answer may be $21$, but no matter how I place and arrange 3x1 pieces, I cannot fit 21th piece.

So is it really $20$? If so, what do I need to know to be able to show that?

geerky42 · Answer

Any ideas, guys?

@Loser66 @amistre64 @abb0t @jim_thompson5910 @ganeshie8

triciaal · Answer

I think 20  -  3 x 1 pieces.  the left over is 1 -  2 x 2 piece

triciaal · Answer

|dw:1432959333256:dw|