| You have 24 coins and a double balance scale. 23 of the coins weigh exactly the same amount; the
24th is slightly heavier. What is the minimum number of weighings you must do on the scale to figure
out with certainty which coin is the heavier one?
Solution: 3 weighings
First weighing: 8 v. 8 coins (w/ 8 off scale)
Second weighing: 3 v. 3 coins (w/2 off scale)
Third weighing: 1 v. 1 coin (w/0 or 1 coin off scale, depending on what happens in the second
weighing)
Congratulations to Ridhima Sakhuja for being the first one with the correct solution. She wins a No
Homework pass.
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