the half life of radium-226 is 1600 years. after how many half-lives would 25% of the radium-226 remain?

Scientists observed a rock stratum and discovered some fossils. the image shows the fossils they discovered. what can you interpret from the image? an illustration showing layers rock with fossils embedded in some rock layers1. the dinosaur and the mammoth existed after the trilobites.2. the dinosaur and the armored fish existed before the trilobites.3. the trilobites and the armored fish died before the dinosaur.4. the trilobites and the armored fish were born after the dinosaur.5. the early mammoth is older than the trilobites.