Discussion
There are eight bags of rice looking alike, seven of which have equal weight and one is slightly heavier. The weighing balance is of unlimited capacity. Using this balance, the minimum number of weighings required to identify the heavier bag is
Answer: A
The heavier bag can be found in 2 weighings.
Divide the eight bags into groups of 3, 3 and 2.
- Weigh 3 against 3. If one side is heavier, the heavy bag is among those 3. If they balance, it is among the 2 left aside.
- From 3 suspects, weigh 1 against 1: the heavier one is it, and if they balance it is the third. From 2 suspects, weigh 1 against 1 and the heavier is it.
One weighing has three outcomes (left heavy, right heavy, balance), so two weighings can distinguish 3 × 3 = 9 cases, enough for 8 bags. Three weighings is the halving approach (4 v 4, 2 v 2, 1 v 1), which does not use the balance outcome.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development