100%.....50%.....25%......12.5%......6.25%......3.125%......1.5625%
...........1............2...........3..............4.................5................6..................
After six half-lives would be found 1.5625% of readioactive species.
57.0 is it rounded to three sig figs. You count three spaces then round from there, which would be the zero and you would round down because the four is there.
I don’t understand. Is there a picture? Where are the options?