Question

A population of a village decreases at the rate of 20% per annum .if its population 2 years ago was 20000.what is its present population

Answer 1

Every year population decreases by 20%=> if 20000 next year =20000-20%20000.
=>20000-4000=16000.
Next year;16000-20%16000.
=>16000-3200=12800.
The present population is 12800.