Depends on the pressure when the tires are fully inflated.
Less, actually.
Measurably less than "less than 10kg"? Yes, I understand that air at 30psi weighs more. Let's assume that the tires hold 3 liters of air (standard for a mt. bike, the yike looks like it holds a lot less actually). The 30psi will add 3.75 grams. Less than two pennies.