Therefore, the bones were 6612.5 years old at the time they were discovered.
<h3><u>Half life</u></h3>
Given that the radioactive element carbon-14 has a half-life of 5750 years, and a scientist determined that the bones from a mastodon had lost 57.5% of their carbon-14, to determine how old were the bones at the time they were discovered, the following calculation must be made:
50 = 5750
100 = 11500
57.5 = X
57.5 x 11500 / 100 = X
6612.5 = X
Therefore, the bones were 6612.5 years old at the time they were discovered.