Question

The population of a place in a particular year increased by 15 %. Next year it decreased by 15%. Find the net increase or decrease per cent in the initial population.​

Answer 1

Let the initial population be 100

First year it increases by 100 of 15% = 100×15/100=15

=>100+15=115

Next year it decreases by 15% of 115

=115×15/100 =69/4=17.25

=> 115-17.25 = 97.75

decrease=100-97.75=2.25

decrease % = (2.25/100)×100%=2.25%