An isotope of potassium `K_(40)` undergoes two parallel types of decy, one by electron capture and other by `beta` decay with half lives as `1.3xx10^(9)` years and `(1.3)/(9)xx10^(9)` years respectively If in a sample of a mineral, mass ratio of `K : Ar Ca "is" 5 "and" 16` then calculate age of the mineral if it is known that all `Ca^(40)` in the mineral is not from the radioactive decay of potassium.
[Express your answer in terms of `10^(7)` years for e.g. if you answer is `2xx10^(9)` years fill 0200 in OMR sheet]

Answer

26