Percentage & Percentage change
Percentage & Percentage change Percent (read as per cent) means ‘every hundred’, or, essentially, ‘out of 100’. If we are given a fraction, we can simply convert it to a percentage by multiplying 100. Say, we have ½, which, when multiplied with 100 becomes ½ x 100 = 50%. What do we mean by a percentage change? Say, a person has 20 chocolates. If his number of chocolates is increased by 10%, what does it mean? First of all, let us see what is doesn’t mean: after the increase, the number of chocolates with him is NOT 20 + 10 = 30, nor is it 20 + 10 / 100 = 20.1 When we talk of a percent increase, we must understand on what BASE VALUE is the percentage change working on. In this case, obviously, the 10% increase is 10% of the number of chocolates he has, i.e. 20. Thus, the number of chocolates with him would become: 20 + 10% of 20 = 20 + 20 x 10 / 100 = 22 Observe that: 20 + 20 x 10 / 100 = 20 x (1 + 10 / 100 ) = 2...