Percentage change in the percentage

Question

Annual percentage change in revenue at Burger House from 2010 to 2011 is 6%, and from 2011 to 2012 is 9%. What is the percentage change in the revenue from 2010 to 2012?

Answer 1

revenue in 2010 got multiplied by 1.06 to effect 6% gain.

 

then this result was multiplied by 1.09 to get 2012's revenue.

 

thus the effect was to multiply by the product 1.06(1.09) = 1.1554 which is 15.54 % gain from 2010 to 2012.