Question 341284
c = 20e^-0.1t 

..
{{{c= 20*e^((-0.1*1))}}}
{{{c=20*e^(-0.1)}}}
c=18.096{{{mu}}}g
..
Plug the value of 2 seconds
{{{c= 20*e^((-0.1*2))}}}
{{{c=20*e^(-0.2)}}}
c=16.374{{{mu}}}g

18.096-16.374=1.722mug/second