If you have 600 g of a substance with a half life of 8,500 years how long will it take to decay to 37.5g

The sun's gravitational pull is weaker on the planets that are closer to it, i think.

Shania is trying to determine the oldest geologic unit on this map and the reason to why is she unable to do so is that  the units are all the same age.. when there is the same age, there will be no oldest geologic unit and that i cannot be credible.