The bacteria increases at the rate proportional to the number of bacteria present. If the original number '…
The bacteria increases at the rate proportional to the number of bacteria present. If
the original number ' $\mathrm{N}^{\prime}$ doubles in 4 hours then the number of bacteria in 12 hours
will be
$3 \mathrm{~N}$
$4 \mathrm{~N}$
$6 \mathrm{~N}$
$8 \mathrm{~N}$
Solution
Number of bacteria at the beginning $=N$. The number doubles in every $4 \mathrm{hrs}$.
$\therefore$ Number of bacteria after $4 \mathrm{hrs}=2 \mathrm{~N}$, after $8 \mathrm{hrs}=4 \mathrm{~N}$, after $12 \mathrm{hrs}=8 \mathrm{~N}$