Chemistry - Chemical Kinetics Question with Solution | TestHub

The half-life periods of two first-order reactions are in the ratio 3 : 2. If ${\mathrm{t}}_1$ is the time required for 25\% completion of the first reaction and ${\mathrm{t}}_2$ is the time required for $75\%$ completion of the second reaction, then the value of, $\left({\mathrm{t}}_1+{\mathrm{t}}_2\right)$ is $\_\_\_\_$ seconds.

Given : Half life of first reaction is 21 sec., ln2 = 0.7, ln3 = 1.1)