Question 566011
The decay function could be represented as
fraction remaining remaining={{{e^(-kt)}}}
With {{{t}}} in hours, we know that at {{{t=1}}}, fraction remaining={{{1-0.055=0.945}}}
{{{0.945=e^(-k)}}} <---> {{{ln(0.945)=-k}}}
We want to find t so that 50% is left, so
{{{0.5=e^(-kt)}}} <---> {{{ln(0.5)=-kt}}}
Combining both equations
{{{ln(0.5)/ln(0.945)=t}}}
{{{t=12.25}}}