Pentomino Box Packing : 10×8 −20

3 solutions.

1. .WW..VVVY.
   WW..UUUVYY
   WX..UZUVYI
   XXX..ZZZYI
   TXNNN..ZLI
   TTTFNN..LI
   TPPFFF..LI
   .PPPF..LL.

2. .WW..VVVY.
   WW..UUUVYY
   WX..UZUVYI
   XXX..ZZZYI
   NXFFP..ZLI
   NFFTPP..LI
   NNFTPP..LI
   .NTTT..LL.

3. .WW..VVVY.
   WW..UUUVYY
   WX..UZUVYI
   XXX..ZZZYI
   PXNNN..ZLI
   PPTFNN..LI
   PPTFFF..LI
   .TTTF..LL.