Answer:
A - 50
B - 12 (or 12.5 if any decimals are included)
C - 3
D - 2
E - 0
In the table it seems that the values for Radioactive Atoms (Predicted) are the values for
multiplied by 100. For smaller numbers, they are rounded to two decimals such as for 0.0625 which if multiplied by 100 should be 6.25. This value is rounded to 6.
Similar is 0.0078125 which is rounded to 0.01 only. When this is multiplied by 100, it gives the value of 1. Thus, the values for D and E are most probably also 2 and 0. If the same logic is followed as for value 0 as they are rounded to 0.02 and 0.00 before multiplying by 100.
Another way to look at this is that the value is half of that of the previous life cycle. Thus, A is half of 100 which is 50 and 25 (life-cycle 2) is half of 50. My answers are also respecting this trend.