(a(i))[1]
You are told that the rate of increase of $N$ with respect to $t$ is proportional to $(N - 150)$. Write a differential equation involving $N$, $t$ and a constant of proportionality.
(a(ii))[7]
At the start, when $t = 0$, there were $650$ plants. It was observed that, at a point when the count had reached $900$, the plants were increasing at $60$ per year. Write $N$ as a function of $t$.
(a(iii))[2]
The naturalists wanted the number of plants to rise from $650$ to $2000$ in $15$ years. Is this target achieved?