"You need 3 weights: 1#, 3#, 9#.

To weigh X, where X is

X Lpan Rpan 1 1# X 2 3# X,1# 3 3# X 4 3#,1# X 5 9# X,1#,3# 6 9# X,3# 7 9#,1# X,3# 8 9# X,1# 9 9# X 10 9#,1# X 11 9#,3# X,1# 12 9#,3# X"

A few people also pointed out that these 3 weights will measure objects up to 13 pounds. A few others pointed out (or gave as their sole answer, which was counted as correct), that you can weigh all 12 with a 1, 3, and 8 pound set. Here is an explanation of such from Andy Muenz, Glenolden, PA:

" Left Side Right Side

Object

1lb 1lb weight

2lb + 1lb weight 3lb weight

3lb 3lb weight

4lb 3lb weight + 1lb weight

5lb + 3lb weight 8lb weight

6lb + 3lb weight 8lb weight + 1lb weight

7lb + 1lb weight 8lb weight

8lb 8lb weight

9lb 8lb weight + 1lb weight

10lb + 1lb weight 8lb weight + 3lb weight

11lb 8lb weight + 3lb weight

12lb all 3 weights"

Also, Gus Molina and Shirley Wolf pointed out that in addition to these two methods, a THIRD method exists: a 2, 3 and 9 pound set. Only these 3 sets were found. Can you find any others?

Winner: Al Siller, Rockville, MD

Contest Statistics: 20 answers submitted, 10 answers correct, 50.00% accuracy. Chance of a correct answer winning: 10.00%.