Answers to Contest Center puzzles, riddles and brainteasers
W I N
I   O
N O W
Riddle Answers
The Contest Center
59 DeGarmo Hills Road
Wappingers Falls, NY 12590
W I N
I   O
N O W


Pan Balance
       Many people immediately jump to the answer that you should buy weights of 1, 2, 4, 8, 16, etc. ounces. This is because they learned in school that these can be added to make any whole number, for example 21 is 16+4+1. So you could weigh a 21-ounce object by putting it in one pan, and placing weights 1, 4 and 16 in the other pan.
       People who consider the problem more carefully will realize that you can put the weights on either pan. Using weights 1, 3, 9, 27, 81, etc. you can add and subtract them to make any whole number, for example 21 is 27+3-9. So you could weigh a 21-ounce object by placing it in one pan along with the 9-ounce weight, and putting 3 and 27 in the other pan.



Send email Send us an email for any comments about these answers, or to submit new riddles.
Share your favorite riddles with other puzzle-lovers.
Be sure to change the $ to an @ in our email address.


Quick Links
Interactive Online Games
<<< PREV HOME MAP NEXT >>>


© Copyright 2012 The Contest Center