Question

Population of a city in the years 2005 and 2010 are 1,35,000 and 1,45,000 respectively. Find the approximate population in the year 2015. (assuming that the growth of population is constant).

Answer 1

Taking year as x and population as y 

We are given when x = 2005, y = 1,35,000 and when x = 2010, y = 1,45,000

y – 135000 = 2000 (x – 2005) 

y = 2000(x – 2005) + 135000 

At x = 2015, y = 2000 (2015 – 2005) + 135000 

(i.e) y = 2000 (10) + 135000 = 20000 + 135000 = 1,55,000 

The approximate population in the year 2015 is 1,55,000