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

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 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 emission simultaneously, the time after which only one-fourth of the sample remain is

The hall 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 emission simultaneously, the time after which only one-fourth of the sample remain is

Half-life of a radioactive sample is 200 days. Its decay constant is

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.