Because of cholesterol problems, I must take a certain medicine. Every week I buy a box, which lasts me for seven days.
However, things are not so bad. The laboratory that produces this medicine has an standing offer: for every five empty boxes, they give you a free new box.
Thus, I get six boxes paying just for five; it means a 16.67% savings for me... right or wrong?
The individual purchases five empty boxes: B(1), B(2), B(3), B(4), and B(5), and he gets the free box B(6).
After the individual has used up Boxes B(1) to B(5), he only has the free Box B(6) and must now buy 4 boxes boxes B(7) to B(10), so that he will be eligible to get a free box after he used up B(6) to B(10) and returned them.
Accordingly, to be eligible to get a free box, the individual must purchase 4 box each time.
1
Consequently, his savings are ----------*100 = 20%.
1 + 4
Puzzle Solution
