home *** CD-ROM | disk | FTP | other *** search
-
- SOLUTIONS.DOC Page 1 of 3
-
- THE ODD BALL SOLUTIONS
- METHOD 1.
-
- Theory - After the first 'weigh', think about groups of three
- for the balls and change sides for the next 'weigh'.
- Follow steps 1 thru 13 to get the idea.
-
- 1. Weigh 1 2 3 4 against 5 6 7 8
- a. If scales are balanced - go to step 2
- b. If right side is heavy - go to step 6
- c. If left side is heavy - go to step 10
-
- 2. Weigh 1 2 3 4 against 5 9 10 11
- a. If scales are balanced - go to step 5 (ODD BALL is 12)
- b. If right side is heavy - go to step 4 (ODD BALL is heavy)
- c. If left side is heavy - go to step 3 (ODD BALL is light)
-
- 3. Weigh 1 2 3 9 against 5 6 7 10
- a. If scales are Balanced - ODD BALL is 11/light
- b. If right side is heavy - ODD BALL is 9/light
- c. If left side is heavy - ODD BALL is 10/light
-
- 4. Weigh 1 2 3 9 against 5 6 7 10
- a. If scales are Balanced - ODD BALL is 11/heavy
- b. If right side is heavy - ODD BALL is 10/heavy
- c. If left side is heavy - ODD BALL is 9/heavy
-
- 5. Weigh 1 2 3 4 against 5 6 7 12
- a. If scales are Balanced - OOOPS
- b. If right side is heavy - ODD BALL is 12/heavy
- c. If left side is heavy - ODD BALL is 12/light
-
- 6. Weigh 5 6 7 1 against 8 9 10 11
- a. If scales are Balanced - go to step 8 (ODD BALL is 2 3 4 and light)
- b. If right side is heavy - go to step 9 (ODD BALL is 1/light or 8/heavy)
- c. If left side is heavy - go to step 7 (ODD BALL is 5 6 7 and heavy)
-
- 7. Weigh 1 2 3 5 against 6 8 9 10
- a. If scales are Balanced - ODD BALL is 7/heavy
- b. If right side is heavy - ODD BALL is 6/heavy
- c. If left side is heavy - ODD BALL is 5/heavy
-
- 8. Weigh 2 5 6 7 against 3 9 10 11
- a. If scales are Balanced - ODD BALL is 4/light
- b. If right side is heavy - ODD BALL is 2/light
- c. If left side is heavy - ODD BALL is 3/light
-
- 9. Weigh 1 2 3 4 against 9 10 11 12
- a. If scales are Balanced - ODD BALL is 8/heavy
- b. If right side is heavy - ODD BALL is 1/light
- c. If left side is heavy - OOOPS
-
- 10. Weigh 1 9 10 11 against 2 3 4 8
- a. If scales are Balanced - go to step 12 (ODD BALL is 5 6 7 and light)
- b. If right side is heavy - go to step 13 (ODD BALL is 2 3 4 and heavy)
- c. If left side is heavy - go to step 11 (ODD BALL is 1/heavy or 8/light)
-
- SOLUTIONS.DOC Page 2 of 3
-
- 11. Weigh 1 2 3 4 against 9 10 11 12
- a. If scales are Balanced - ODD BALL is 8/light
- b. If right side is heavy - OOOPS
- c. If left side is heavy - ODD BALL is 1/heavy
-
- 12. Weigh 1 2 3 5 against 6 8 9 10
- a. If scales are Balanced - ODD BALL is 7/light
- b. If right side is heavy - ODD BALL is 5/light
- c. If left side is heavy - ODD BALL is 6/light
-
- 13. Weigh 1 2 5 6 against 3 7 8 9
- a. If scales are Balanced - ODD BALL is 4/heavy
- b. If right side is heavy - ODD BALL is 3/heavy
- c. If left side is heavy - ODD BALL is 2/heavy
-
-
- FLOW CHART SOLUTION
-
- Top is left scales
-
- 1 2 3 4 - Heavy 1/heavy
- ------------- - Equal 8/light
- | 9 10 11 12 - No Way
- |
- 1 9 10 11 - Heavy 1 2 3 5 Heavy 6/light
- --------------- - Equal - -------- - Equal 7/light
- | 2 3 4 8 - Heavy 6 8 9 10 - Heavy 5/light
- | |
- | | 1 2 5 6 - Heavy 2/heavy
- | -------------- - Equal 4/heavy
- | 3 7 8 9 - Heavy 3/heavy
- |
- | 1 2 3 9 - Heavy 10/light
- | -------------- - Equal 11/light
- | | 5 6 7 10 - Heavy 9/light
- | |
- 1 2 3 4 - Heavy 1 2 3 4 - Heavy 1 2 3 4 - Heavy 12/light
- ------- - Equal - --------- - Equal - --------- - No Way
- 5 6 7 8 - Heavy 5 9 10 11 - Heavy 9 10 11 12 - Heavy 12/heavy
- | |
- | | 1 2 3 9 - Heavy 9/heavy
- | -------------- - Equal 11/Heavy
- | 5 6 7 10 - Heavy 10/heavy
- |
- | 1 2 3 5 - Heavy 5/heavy
- | -------------- - Equal 7/heavy
- | | 6 8 9 10 - Heavy 6/heavy
- | |
- | 1 5 6 7 - Heavy 2 5 6 7 - Heavy 3/light
- --------------- - Equal - --------- - Equal 4/light
- 8 9 10 11 - Heavy 3 9 10 11 - Heavy 2/light
- |
- | 1 2 3 4 - No Way
- -------------- - Equal 8/heavy
- 9 10 11 12 - Heavy 1/light
-
- SOLUTIONS.DOC Page 3 of 3
-
- METHOD 2.
-
- The Second Method is to make 3 weighs as follows:
-
- WEIGHING LEFT SCALES RIGHT SCALES
- First 1 2 3 4 5 6 7 8
- Second 1 2 5 6 7 9 10 11
- Third 1 7 9 12 4 5 8 10
-
- Then if LEFT is heavy write a "1", If RIGHT is heavy write a "2" and
- if the scales balance write a "0" and use the following table.
-
- BALL HEAVY LIGHT
- 1 111 222
- 2 110 220
- 3 100 200
- 4 102 201
- 5 212 121
- 6 210 120
- 7 221 112
- 8 202 101
- 9 021 012
- 10 022 011
- 11 020 010
- 12 001 002
-
-