# math

posted by
**Marie**
.

39mg radioactive with 1/2 life is decay total in 2.5 years. How many mg it remain if half of the amount is decay in 2 years?

Thank you!

posted by
**Marie**
.

39mg radioactive with 1/2 life is decay total in 2.5 years. How many mg it remain if half of the amount is decay in 2 years?

Thank you!