You can put this solution on YOUR website! Let's say that on the 15th day, there are 'x' pennies in the basket. On the 14th day, there are pennies in the basket (ie half of the pennies are in the basket). Notice how if you double the number of pennies on the 14th day, you get pennies.
Now on the 13th day, there are pennies (ie take half of to get ). This is a fourth of the number of pennies that are present on the 15th day.
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