A radioactive element which can decay by two processes, has half-life t1 for first process and half - life t2 for second process. Let 〈t〉 be the effective average - life of this element. The correct statement is
1
\(\langle t\rangle<\frac{t_1 t_2}{t_1+t_2}\)
2
\(\langle t\rangle=\frac{t_1 t_2}{t_1+t_2}\)
3
\(\langle t\rangle>\frac{t_1 t_2}{t_1+t_2}\)
4
\(\langle t\rangle=\ln 2\left(\frac{t_1+t_2}{t_1 t_2}\right)\)