The ratio of the components in a mixture, which consists of two elements, is to be determined. The atomic number of the elements is large, their atomic masses are the same and amount of the sample is only 58 mg. We know that both elements $\beta$ decay when they are bombarded by neutrons. They behave similarly when absorbing neutrons. The half-life of element A is half an hour and the half-life of element B is an hour. Right after the neutron irradiation the $\beta$  emission is measured. At this time 80 particles are measured in 2 sec, and after an hour only 29 particles are measured during 2 sec. The mass of the element A (in mg) in the sample is $K\times 11$ , then the value of K is [Assume that spontaneous decay statistical law is obeyed by nuclei of both the elements]