The mean lives of a radioactive substance are 1620 years and 405 years of `alpha`-emission and `beta`-emission respectively. Find out the time during which three-fourth of a sample will decay if it is decaying both by `alpha`-emission and `beta`-emission simultaneously.

The mean lives of a radioactive substance are 1620 years and 405 years for alpha emission and beta emission respectively. Find out the time during which three fourth of a sample will decay if it is decaying both by alpha -emission and beta -emission simultaneously. (log_e4=1.386).

The mean lives of an unstable nucleus in two different decay processes are 1620 yr and 405 yr, respectively. Find out the time during which three-fourth of a sample will decay.

The half lives of a radioactive sample are 30 years and 60 years from alpha - emission and beta - emission respectively If the sample decays both by alpha-emission and beta -emission simultaneously, the time after which, only one-fourth of the sample remain is

The mean lives of a radioactive substance are T^(1) and T^(2) for alpha- emission and beta- emission respectively. If it is decaying by both beta- emission and beta - emission simultaneously then find its mean life and decay constant ?

The half-lives of radioactive sample are 30 years and 60 years for two decay processes. If the sample decays by both the processes simultaneously. The time after which, only one-fourth of the sample will remain is

After 1 alpha and 2 beta emissions.

A radioactive material has mean lives of 1620 years and 660 years for alpha and beta emissions respectively the material decays by simultaneous alpha and beta emission. The time in which (1)/(4)th of the material remains intact is-

A radioactive material has a half life of 600 years and 300 years for alpha and beta emissions respectively. The material decays by simultaneous alpha and beta emissions respectively . The material decays by simultaneously alpha and beta emissions . What is time in which 3/4 th of the material will decay ?

Half lives for alpha and beta emission of a radioacative materila are 16 years and 48 years respectively. When material decays giving alpha and beta emission simultaneously, time in which 3//4^(th) material decays is .