$a$

value $as$ Population $1,$ but the value $ofbis150$ times larger than the value $ofbin$ Population

$If$ Population $2$ starts off with $an$ initial population $of30,$ will the population subsequently

increase $or$ decrease?

Question $5$: $12$ Marks

Assume that a radioactive substance decays with a constant $of$ decay $k=0,004$ when time $is$ measured $in$

years.

$(5\mathrm{.}1)$ How long does $it$ take for the substance $to$ decay from $5$ grams $to2$ grams?

$(5\mathrm{.}2)If10\%ofan$ original quantity $N_{0}is$ present today, when was $N_0$ formed initially?

Question $6$: $12$ Marks

A culture initially has $P_0$ number $of$ Acinetobacter baumannii bacteria. $Att=1$ hour, the number $of$ bacteria

$is$ measured $tobe\frac{4}{3P_0}.If$ the rate $of$ growth $is$ proportional $to$ the number $of$ bacteria $P(t)$ present $att$