Question 1077705
Half the mass lost in 16 hours is (1/2)=e^(-16k)
-ln2=-16k
k=ln2/16=0.04332 for X
k=ln2/21=0.03301 for Y
We want e^(-0.04332t)/e^(-0.03301t)=1/3
3e^(-0.04332t)=e^(-0.03301t)
So:
ln 3-0.04332t=-0.03301t
1.0986122886681096913952452369225=0.01031t
t=106.55793 hours. ☺☺☺☺