The correct answer is: C. 10%
A good quality brick when immersed in water for a period of 16 hours should not exceed the weight of dry brick by more than 10%. This is because the brick will absorb some water, which will increase its weight. The amount of water absorption will vary depending on the type of brick, but it is typically in the range of 5-10%. If the brick absorbs more than 10% water, it may become unstable and could collapse.
Option A is incorrect because it is too high. A brick that absorbs 20% water will be significantly heavier than a dry brick, and
it may not be able to support its own weight.Option B is incorrect because it is
too low. A brick that absorbs 15% water will be noticeably heavier than a dry brick, but it is unlikely to be unstable.Option D is incorrect because it is not a specific percentage. The weight of a good quality brick when immersed in water for a period of 16 hours should not exceed the weight of dry brick by more than 10%.