Help! exponent grade

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

What could explain what happened when the time was equal to 120 minutes

The table shows the age and finish time of ten runners in a half marathon. identify the outlier in this data set. drag into the table the ordered pair of the outlier and a reason why that point is an outlier.