Each day Allan eats 60% of the previous days chocolates. This means that each day Allan is left with 40% of the remaining chocolates of the previous day.
This is a successive percentage change and can be written as a straight line equation.
x * \(\frac{40}{100}\) * \(\frac{40}{100}\) * \(\frac{40}{100}\) = 16
Where x is the initial number of chocolates and 16 is the final number of chocolates after 3 days
Therefore x * \(\frac{64}{1000}\) = 16
x = 250
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When using the theory of successive discounts, if a % is decreasing then decrease that amount from 100% and if a % is increasing add it to 100%.
For eg a stock market price of $1000, fir decreased by 10% on the 1st day and then increased by 20% on the second day. What is it's price at the end of the second day?
Since the Percentages are successive, we simply write it as 1000 * \(\frac{90}{100}\) * \(\frac{120}{100}\) = $1080
We have decreased 10% from 100% to give 90% and added 20% to 100% to get 120%.
Note: When doing successive percentages based sums, do not add or subtract the percentages, for eg in the example above, doing -10 + 20, which gives an overall percentage of +10% is incorrect.
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Arun Kumar