392 / 500 double and take one decimal place to see percentage
52/500
56/500 e.g. 56*2 = 112 now take 1 decimal so it is 11.2%
now divide each by 20
It would kind of help if there was a graph that we could choose to help you
I believe it is a triangular prism
<span>You would have to wait 318 years for 1/5 (20%) of the Radium to disappear. 1590 is the point where half of the Radium would decay, so if you take 20% of that, it would equate out to 318 years. Radium has a long half life!</span>
