math
posted by Tran .
the bridge was built, the wood
contained 15 grams of carbon14. How much carbon
14 would it have contained when it was found by the
archaeologists? Round to the nearest hundredth

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.
Carbon14 has a halflife of about 5,600 years.