`N=N_(0)" का "1%=N_(0)xx(1)/(100)=(N_(0))/(100)`
`N=N_(0)((1)/(2))^((t)/(T))`
या `" "(N_(0))/(100)=N_(0)((1)/(2))^((t)/(T))`
या `" "(1)/(100)=((1)/(2))^((t)/(T))`
या `" "100=(2)^((t)/(T))`
या `" "log100=(t)/(T)log2`
या `" "log10^(2)=(t)/(T)xx0.3010`
`2log10=(t)/(T)xx0.3010`
`2xx1=(t)/(T)xx0.3010`
या `" "t=(2T)/(0.3010)=6.64T`.