the bridge was built, the wood

Question

contained 15 grams of carbon-14. How much carbon-
14 would it have contained when it was found by the
archaeologists? Round to the nearest hundredth

Answer 1

When was the bridge built? You have omitted important information. In fact, it looks like you have omitted at least one sentence and part of another.

Carbon-14 has a half-life of about 5,600 years.