What was the main demand of the Akali Dal during the 1980s in Punjab?

If in a population of size ”N” the birth rate is represented as “b” and the death rate as “d”, the increase or decrease in “N” during a unit time period ”t” will be:

The equation given above can also be represented as:

What does ”r” represent. Write any one significance of calculating ”r” for any population? 

FInd the number of all possible matrices of order

$3\times 3$ with each entry $0$ or $1$.