The rate of decay of a radioactive sample is R_(1) at time t_(1) and R_(2) at time t_(2). Calculate the mean liffe of sample.

The rate of decay of a radioactive sample is R_(1) at time t_(1) and R

1.	The rate of decay of a radioactive sample is R_(1) at time t_(1) and R_(2) at time t_(2). Calculate the mean liffe of sample.
Answer» ANSWER :`(t_(1) - t_(2))/(2.303 [LOG R_(2) - log R_(1)])`