Question

In 10 years, 25% of a radioactive substance decays. What is its half-life?

A. 25 years
B. 24 years
C. 20 years
D. 29 years

Answer 1

(1/2)^(10/x) = .75
x = 24

Answer 2

You first have to find your rate

.75 = e^ (r)(10)

Then find the time for half- life

.5 = e^ (r from above)(t)

Answer 3

Thanks

Answer 4

24