Question

a number increased by 20% and then decreased by 20 %. find the net increase or decrease percent

Answer 1

Let the number be 100 %
It is given that first the number is increased by 20 %
Hence, 20 % of 100 % = (20/100) x (100/100)
                                     = 20/100
                                     = 20 %
So, increase in number = 100 % + 20 %
                                      = 120 %
Also given that the number is decreased by 20 %
Hence, 20 % of 120 % = (20/100) x (120/100)
                                     = 24/100
                                     = 24 %
So, decrease in number = 120 % - 24 %
                                       = 96 %
which shows that the net decrease in percent of the original number is 96%.
Hope it will help you.

Answer 2

Let the number to = 100

Increase in the number= 20% of 100
= (20/100)×100= 20

Increased Number = 100 + 20= 120


The resulting number decreased by 20%

Decrease in the number= (20/100)×120))= 12×2=24


New number= 120-24 = 96

Now, net decrease =100-96 = 4

Net %Decrease = (net decrease/ Original number × 100) %


=( ( 4/ 100 )×100) %

= 4%.

Hence, net percent decrease= 4%

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Hope this will help you....