Percentage Practice Test 5 with solutions

Let the selling price of a book in year 2008 = x
Decrease percentage in the sale from year 2008 to 2009 = 80%
So, the sale of a book in year 2009 = (x – 80% of x)
=x−

80

100

x=

x

5

Let the selling price of a book in the year 2010 = x
Increase percentage of the sale from year 2009 to 2010 =

x− x 5

x 5

×100
Required increase percentage = 400%