N=N₀2^(-t/T). (1/3)N₀=N₀2^(-t/T). 0,333=2^(-t/T). ln0,333=ln2^(-t/T).
-1,0986=-(t/T)ln2. -1,0986=-0,693(t/T). t/T=1,582. t=1,582T.
t=1,583•14,36=22,7 сут.
N=N₀2^(-t/T). (1/3)N₀=N₀2^(-t/T). 0,333=2^(-t/T). ln0,333=ln2^(-t/T).
-1,0986=-(t/T)ln2. -1,0986=-0,693(t/T). t/T=1,582. t=1,582T.
t=1,583•14,36=22,7 сут.