GoldyOrNugget
Señor Member
- Joined
- Jul 14, 2012
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- HSC
- 2012
This question was on a selection exam for the Australian informatics olympiad team many years ago.
There's a pile of diamonds in front of you -- 30 fake diamonds and 2 real diamonds. Each fake diamond weighs 10g. The 2 real diamonds weigh 5g and 15g respectively.
You have a set of scales on which you can place any number of diamonds, and it will tell you their combined weight.
What's the minimum number of weighings required to find the two real diamonds? (including determining which is the 5g and which is the 15g)
For bonus marks, give a method that yields this minimum.
There's a pile of diamonds in front of you -- 30 fake diamonds and 2 real diamonds. Each fake diamond weighs 10g. The 2 real diamonds weigh 5g and 15g respectively.
You have a set of scales on which you can place any number of diamonds, and it will tell you their combined weight.
What's the minimum number of weighings required to find the two real diamonds? (including determining which is the 5g and which is the 15g)
For bonus marks, give a method that yields this minimum.