A town with a population of 12 000 has been growing at an average rate of 2.5%

To calculate the population growth, we can use the formula:

New Population = Initial Population + (Initial Population * Growth Rate)

First, let's convert the growth rate of 2.5% into a decimal by dividing by 100:

2.5% = 2.5/100 = 0.025

Now we can calculate the new population:

New Population = 12,000 + (12,000 * 0.025)
New Population = 12,000 + 300
New Population = 12,300

Therefore, the new population of the town is 12,300.