Given: Work done in sliding a block up an inclined plane
$W = 320$ Joule
Mass of block $M = 2\, kg$
Height of inclined plane $= 10\, m$
The potential energy stored in the block is given by
$ U=mgh=2\times 10\times 10=200\,J $
Hence, work done against friction is given by
$ =W-U=300-200=100\,J $