A population of 1000 individuals has 110 births and 10 deaths in a year. Its growth rate (r) is equal to?

that is a constant growth rate of 100 per year.

However that is not usual. As the population grows they have more babies per year as a rule and the growth numbers tends to be proportional to population. That means
rate = constant * size
the solution to that sort of problem is called "exponential"
size = original size * e^rt
where r is a growth constant
In other words the bigger the population the faster it grows.
So more likely we are talking about both growth numbers and death numbers being proportional to population and the 1000 and 100 is only our initial condition.
then
p = Pi e^rt
when t = 0, e^0 = 1 and p = Pi = 1000
so
p = 1000 e^rt
if you know differential calculus that means
dp/dt = 1000 r e^rt
when t = 0 dp/dt = 100
so
100/1000 = r e^0
0.1 = r

To calculate the population growth rate (r), you can use the following formula:

r = (births - deaths) / population

In this case, the number of births is 110 and the number of deaths is 10. The population size is 1000.

Plugging in these values into the formula:

r = (110 - 10) / 1000
r = 100 / 1000
r = 0.1

Therefore, the growth rate (r) is equal to 0.1 or 10%.

To determine the growth rate (r) of a population, we can use the following formula:

r = (number of births - number of deaths) / population size

In this case, the number of births is 110, the number of deaths is 10, and the population size is 1000.

r = (110 - 10) / 1000
r = 100 / 1000
r = 0.1 or 10%

Therefore, the growth rate (r) of the population is 0.1 or 10%.