There are 9 coins. Out of which one is odd one i.e weight
is less or more. How many iterations of weighing are
required to find odd coin?
Answer Posted / samveg gupta
It is always possible to find odd coin in 3 weighings and to tell whether the odd coin is heavier or lighter.
1. Take 8 coins and weigh 4 against 4.
o If both are not equal, goto step 2
o If both are equal, goto step 3
2. One of these 8 coins is the odd one. Name the coins on heavier side of the scale as H1, H2, H3 and H4. Similarly, name the coins on the lighter side of the scale as L1, L2, L3 and L4. Either one of H's is heavier or one of L's is lighter. Weigh (H1, H2, L1) against (H3, H4, X) where X is one coin remaining in intial weighing.
o If both are equal, one of L2, L3, L4 is lighter. Weigh L2 against L3.
 If both are equal, L4 is the odd coin and is lighter.
 If L2 is light, L2 is the odd coin and is lighter.
 If L3 is light, L3 is the odd coin and is lighter.
o If (H1, H2, L1) is heavier side on the scale, either H1 or H2 is heavier. Weight H1 against H2
 If both are equal, there is some error.
 If H1 is heavy, H1 is the odd coin and is heavier.
 If H2 is heavy, H2 is the odd coin and is heavier.
o If (H3, H4, X) is heavier side on the scale, either H3 or H4 is heavier or L1 is lighter. Weight H3 against H4
 If both are equal, L1 is the odd coin and is lighter.
 If H3 is heavy, H3 is the odd coin and is heavier.
 If H4 is heavy, H4 is the odd coin and is heavier.
3. The remaining coin X is the odd one. Weigh X against the anyone coin used in initial weighing.
o If both are equal, there is some error.
o If X is heavy, X is the odd coin and is heavier.
o If X is light, X is the odd coin and is lighter.
| Is This Answer Correct ? | 10 Yes | 1 No |
Post New Answer View All Answers
Radha,Geeta&Revathi went for a picnic.After a few days they forgot the date,day and month on which they went to picnic.Radha said that it was on Thursday,May 8 and Geeta said that it was Thursday May 10.Revathi said Friday Jun 8.Now one of them told all things wrongly,others one thing wrong and the last two things wrongly.If April 1st is tuesday what is the right day,date and month? thought that he should not waste his time and started moving towards his residence at the speed of 3mi/hr.On the way,he gets the coach and reaches home at 6 o'clock.How far is his residence from railway station.
Convert the decimal number 310 to the base 6.
Supposing a clock takes 7 seconds to strike 7. How mlong will it take to strike 10?
A ship started from port and moving with I mph and another ship started from L and moving with H mph. At which place these two ships meet ?
hai frnds pls give me some tips and traps about HP software company interview for freshers.am a B.E CSE fresher.hoe will be the interview?how many days it will be conducted?how will be apps round?technical round?hr round?pls help me if any one known means.send me that pattern by vijay ,chennai
vernacular : place : : fingerprint : ?
What is the difference between control module
In a cycle race there are 5 persons named as J, K, L, M, N participated for 5 positions so that in how many number of ways can M make always before N?
What percent of 60 is 12?
There N stations on a railroad. After adding x stations 46 additional tickets have to be printed. Find N and X.
If a bat costs Rs.30 in the year 1999 and Rs.250 in the year 2000.What is the percent increase in price?
A clock is late by 1 minute 27 seconds in a month. Then how much will it be late in 1 day?
2. Masi specialises __ plesent ,well balanced wines into, about ,in, with 3. By the time I arrived __ the pub she all ready left in, on , at, into 4. erbiage the act of doing something the use many words witout nessecity a vegitable non of the above
3 angles or 3 sides r given. Which will form a triangle?
A ship went on a voyage after 180 miles a plane statrted with 10 times speed that of the ship. Find the distance when they meet from starting point.