The actual weight of the basket is 0.5kg, but the weight where weighing is not allowed is 10.55- 10=0.55(kg).
So the actual standard of 0.5kg is 0.55kg when there is no scale, that is, the standard of 1kg is equal to 1. 1kg without scale.
Therefore, the mass of 10kg in the standard scale is not allowed to be 10/ 1. 1, which is about 9kg.