Question

The population of a state increases annually at the rate of 15%. Its present population is 79350, What was it's population 2 years ago?

Answer 1

Let x be the popation 2 years ago.

Population 1 year ago = x + (15% x)

Present Population= (x + 15%x) + 15% (x + 15%x)

79350= x + 15/100x + 15/100x + (15/100 × 15/100 x)

79350 = x + 15/100x + 15/100x + 225/10000x

793500000 = 10000x + 1500x + 1500x + 225x

13225x = 793500000

x = 60000

Population 2 years ago = 60000