Question

A number is increased by 20% and then decreased by 20%. Find the net increase or
decrease in percentage.​

Answer 1

Answer:

The answer is 4% .

Let the number be x.

1st step : It is increasedd by 20% .

Amount if increase = (20/100)*x

THerefore,the number now after increase = Previous value+amount increased

=x+(20/100)*x =(120/100) *x

2nd step: The resultant number is again decreased by 20% .

Amount decreased= (20/100)*(120/100)*x = 24x/100

The number now = (120/100) x- (24/100)x =96x/100

Now the original number was x and now it is 96x/100.

so net decrease = x-96x/100

Percentage decrease =(net decrease/ original value)* 100

=4%