Two radioactive materials A and B have decay constants `5lambda` and `lambda` respectively. Initially both A and B have the same number of nuclei. The ratio of the number of nuclei of A to that of B will be `1/e`, after the time `x/(8lambda)` then x is :

Two radioactive materials A and B have decay constants 10lambda and lambda , respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of A of that of B will be 1//e after a time :

The radioactive materials X_1 and X_2 have decay constants 5lambda and lambda respectively. If intially they have the same number of nuclei, then the ratio of number of nuclei of X_1 to that of X_2 will be 1/e

Two radioactive material A and B have decay constants 10 lambda and lambda , respectively. If initially they have a the same number of nuclei, then the ratio of the number of nuclei of A to that of B will be 1//e after a time 1/(n lambda) , where n is ___________

Two radioactive materials X_1 and X_2 have decay constants 10 lambda and lambda respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of X_1 to that of X_2 will be 1/e after a time :

Two radioactive materials X_1 and X_2 have decay constants 10 lamda and lamda respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of X_1 to that of X_2 will be 1//e after a time.

Two radioactive materials X_(1) and X_(2) have decay constants 5 lambda and lambda respectively. If initially they have the same number of nuclei, then the ratio of the number of muclei of X_(1) to that of X_(2) will be 1/e after a time