Suppose a planet on which life is based on silicon instead of carbon has been discovered. However, a meteor strike destroyed most of the life on the planet. To determine how long ago the meteor strike occurred, the activity of silicon-32, which has a halflife of 1.6 * 10² a, was measured in samples from the fossil remains of life forms killed in the meteor strike and in existing life forms.
Activity in the fossil samples was found to be 0.015% of the activity in the living samples. How long ago did the meteor strike occur?