A woman had three old coins: a silver dollar, a quarter, and a dime. Each coin was a little battered and had a piece missing. She found that exactly the same fraction had broken away from each coin.
What fraction of each was missing if the value of the remaining bits of coins was now exactly one dollar in total?
For this puzzle it can be assumed that 1/2 a coin is worth 1/2 of its value.
Hint
A dollar is 100 cents, a quarter is 25 cents and a dime is 10 cents.
Answer 7/27 of each coin was missing.
Reasoning
The original value of the three coins was 100 + 25 + 10 = 135 cents, and the new value was 100 cents.
Therefore, 35/135 = 7/27 of the original value has been removed.
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Puzzle 4
Consider an arrow in flight towards a target.
At any given moment of time, a snapshot could be taken of this arrow. In this snapshot, the arrow would not be moving. Let us now take another snapshot, leaving a very small gap of time between them. Again, the arrow is stationary. We can keep taking snapshots for each moment of time, each of which shows the arrow to be stationary. Therefore the overall effect is that the arrow never moves, however it still hits the target!
This is a classic paradox, attributed to Zeno of Elea, a Greek philosopher from Italy. Great minds over the centuries have pondered this paradox, and the scope of a solution is beyond the space available here. It is not even clear that a solution to the paradox actually exists.
