Warning: Do not read other posters' comment unless you give up since it usually contains the answer. Clutchcity.net posters are very smart. Last riddle post for today. Not knowing the credibility of his hostage, Sadam was very surprised to see that the mathematician can answer his question easily. Sadam decides not to let go his hostage so easily. He gave another counterfeit coin riddle. The mathematician was given 10 wallets and inside each wallet are 10 coins. Each coin weighs 10 grams. But of course there is a problem. One of the wallets contains counterfeit coins, and each of the counterfeit coins weighs 11 grams a piece. Thus, a normal weight of wallet is 10*10 grams = 100 grams, but a wallet with counterfeit coins weighs 10*11 grams = 110 grams. Now the mathematician is given a digital scale, and he is supposed to know which wallet contains the counterfeit coins by weighing "only once". How would he do it? Note: This has been answered by Della Previous Logic riddles Riddle #1: Water Container http://bbs.clutchcity.net/php3/showthread.php?s=&threadid=52045 Answered by: drapg, SmeggySmeg Riddle #2: The Wizard and 3 Caps http://bbs.clutchcity.net/php3/showthread.php?s=&threadid=52048 Answered by: codell Riddle #3: The Wizard and 3 Caps (Advanced) http://bbs.clutchcity.net/php3/showthread.php?s=&threadid=52050 Answered by: codell Riddle #4: Average Speed http://bbs.clutchcity.net/php3/showthread.php?s=&threadid=52112 Answered by: Major, codell Riddle #5: Counterfeit Coin http://bbs.clutchcity.net/php3/showthread.php?s=&threadid=52116 Answered by: Invisible Fan
The mathematician was given 10 wallets and inside each wallet are 10 coins. Each coin weighs 10 grams. I assume this is a typo, in that in Wallet #1, there is 1 coin, Wallet #2, 2 coins, etc? (instead of 10 coins in each wallet) If so, then the total weight, if they were all real coins would be 100+90+80+70+60+50+40+30+20+10 grams = 550 grams Weigh all the wallets together. If the total weight is 551, Wallet #1 is the counterfeit. If it's 552, Wallet #2 ... If it's 560, Wallet #10
I'll take a stab at this: he would break up the wallets into 2 groups of 5, whichever group that does not end in a "0" would be the one to have the counterfeit coins in it.
I made a typo in my initial riddle post, but it's been corrected. Each wallet contains 10 coins, that's correct. One of the wallet contains counterfeit coins. So, the total weight of a normal wallet is 10*10 grams = 100 grams. But the total weight of a wallet with counterfeit coins would be 10*11 = 110 grams.
So as not to confuse others, would you mind deleting your initial post regarding making the typo Major? Thanks.
Label the bags 1-10. Take one coin out of bag one, two out of bag 2, 3 out of bag 3, etc. Then weigh the bag. The total weight with no counterfeit coins would be 550 grams. How ever many grams over that your bag weighs is the bag number of the counterfeit coins. ps I just noticed I typed this on my wife's laptop and she has her own cookie. This is dylan. I must get proper credit!!
