Puzzle of the Week: Week 9
You are given 5 bags.There are 10 large balls in each of the bags.In 4 of the bags,the balls each weigh 10 kilograms.In the remaining bag,each ball weighs only 9 kilograms.You must find out which bag has the lighter balls.The problem is that all bags look identical and all the balls look identical.You can use a weighing scale,but it has to be a single tray scale,not a two tray balance scale.Also you may use the scale only once.How can you find out which bag has the lighter balls?
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Posted Friday, 15 January 2010 By Gaurav Goel
Modified: Friday, 15 January 2010
Explain your answer.Lets see who gets it first.The first one to get the correct answer will be declared GENIUS OF THE WEEK on thursday.
solution to puzzle 9
Posted Tuesday, 19 January 2010 By neha Narang
Label the bags as 1, 2, 3, 4 and 5
Now take one ball from bag no1, 2 from bag no2, 3 from bag no3, 4 from nag no4 and 5 balls from baf no5.
Now weigh these balls together.
If the sum is 149, then bag with label 1 is lighter.
If the sum is 148, then bag with label 2 is lighter.
If the sum is 147, then bag with label 3 is lighter.
If the sum is 146, then bag with label 4 is lighter.
If the sum is 150, then bag with label 5 is lighter.
Answer for the Puzzle of the week - 9
Posted Monday, 18 January 2010 By Praveena
Take one ball from 1st bag,
two balls from 2nd bag,
three balls from 3rd bag,
four balls from 4th bag and finally five balls from 5th bag.
Now weigh all the 15 balls.depending on the weight we can find out which bag consists of 9kg balls.
1B 2B 3B 4B 5B
-----------------------
9 10 10 10 10 = 149
10 9 10 10 10 = 148
10 10 9 10 10 = 147
10 10 10 9 10 = 146
10 10 10 10 9 = 145
Answer
Posted Sunday, 17 January 2010 By Akhil c agent47akhil@gmai
Empty 1 bag.then put 1 ball of 1st bag,then 2 balls of 2nd bag,3 of 3rd and 4 of 4th.(if one bag can carry max 10 balls).weigh it.if its 99kg then 1st bag contain 9kg balls.if 98kg then 2nd,if 97kg then 3rd and for 96kg 4th bag.if its 100kg then the bag we used is the answer.
Puzzle of the week: Week 9
Posted Sunday, 17 January 2010 By Prasanna
Take one ball from each bag and place it on the single tray scale one by one...by this the bag with lighter weight can be identified....!! Please correct me if i am wrong and ignore this answer if If it sounds stupid..!!
Week 9 Solution
Posted Sunday, 17 January 2010 By Chirag
This is how we will find the fake balls bag :
Take 1 Ball from the first bag,
2 from the second,
3 from the third,
4 from the forth,
and 5 from the fifth.
Then weigh the whole ( 15 balls ) together.
The weight should ideally be 150 KGs. So by what ever amount this is less we will know which bags it the fake balls came from.
So if the weight is 148 ( 2KGs less), then the fake balls are in 2nd bag. Same logic can be applied to other bags.
Chirag..
Cont'd
Posted Sunday, 17 January 2010 By Wales T George
Weigh the bags together...ie...
Lets Find Out...
Posted Sunday, 17 January 2010 By Wales T George
Take one ball from the first bag, 2 from the second, 3 from the third, 4 from fourth and 5 from the fifth bags...
then weigh the bags... and we'll find out...
Answer to Week 9 puzzle
Posted Saturday, 16 January 2010 By Krishna G Poddar
name the 5 bags a b c d e..
take 1 ball from a ..2 balls from b .. 3 balls from c.. 4 balls from d.. 5 balls from e..
take all the balls.. and keep on the balance..
if the total weight is .. 149 kg or 148 kg or 147 kg or 146 kg or 145 kg.. the bag with 9kg balls will be.. a b c d e.. respectively..
