A radioactive element decays by following three different parallel paths :
`A overset(lambda_(1))(to) B, lambda_(1) = 5 xx 10^(-2) sec^(-1)`
`2A overset(lambda_(2))(to) C,lambda_(2) = 3xx10^(-2) sec^(-1)`
`3A overset(lambda_(3))(to) D, lambda_(3) = 5xx10^(-3) sec^(-1)`
Calculate average life- time of element (in sec.)
`[lambda_(1), lambda_(2), lambda_(3) "are decay constans for respective reactions"]`

Answer

8