Question

An element with mass 310 grams decays by 5.7% per minute. How much of the element is remaining after 9 minutes, to the nearest 10th of a gram?

Answer 1

1st
I need to find out what percentage is left after 1 minute
100 - 5.7 = 94.3% (0.943)

2nd plug into the formula $A = A_{0} r^{t}$

A0 = 310
r = 0.943
t = 9

$A = 310(0.943)^{9} \\ A = 310(0.58966) \\ A = 182.8 g$