\(A\) and \(B\) are two substances undergoing radioactive decay in a container. The half life of \(A\) is \(\mathrm{15 ~…

\(A\) and \(B\) are two substances undergoing radioactive decay in a container. The half life of \(A\) is \(\mathrm{15 ~min}\) and that of \(B\) is \(\mathrm{5 ~min}\). If the initial concentration of \(B\) is 4 times that of \(A\) and they both start decaying at the same time, time it will take for the concentration of both of them to be same is ......... \(\min\)

[JEE Main 2023, 1 Feb (Shift 1)]