16 C plc stocks & L-T Contract (UK)

Hello,

Study text qs in bpp dec 09-jun 10.

Why isn’t provision for losses shown on balance sheet for loss of rottenrow (100)
And for both contract no provission for losses on L-T work in progress, ie I calculated as follows:

Maryhill
Stock
L-T Contract WIP
Cost to date 1400
Less trfr of Cos to date. (2170)
Shown as prov for loss: 770

Any response will be much appreciated. Thanks