1. Categories >> Aptitude Questions >> General Aptitude
  2. Suggest New Category

You have 8 balls. One of them is defective and weighs less
than others. You have a balance to measure balls against
each other. In 2 weighings how do you find the defective one?

Question Posted / nandita

Answers were Sorted based on User's Feedback



You have 8 balls. One of them is defective and weighs less than others. You have a balance to measu..

Answer / balbir singh

Firstly we take 6 balls, placing 3 on each pan of the
balance & check which pan goes up(1st weighing). If no
change it means the balls don't contain the defective
one,therefore the other two contain the defective
ball,which can be found out easily(2nd weighing).
Now if one of the pan goes up,it means it contains the
defective ball(out of 3 balls).We select these 3 & unload
the pans. Now we keep any of the 2 balls(from the selected
balls)on either side of the balance & weigh(2nd weighing).
One of these two will be the defective one and if not the
3rd one leftover is.

Is This Answer Correct ?    67 Yes 6 No

You have 8 balls. One of them is defective and weighs less than others. You have a balance to measu..

Answer / savitha shreyas

Firstly we take 6 balls, placing 3 on each pan of the
balance & check which pan goes up(1st weighing). If no
change it means the balls don't contain the defective
one,therefore the other two contain the defective
ball,which can be found out easily(2nd weighing).
Now if one of the pan goes up,it means it contains the
defective ball(out of 3 balls).We select these 3 & unload
the pans. Now we keep any of the 2 balls(from the selected
balls)on either side of the balance & weigh(2nd weighing).
One of these two will be the defective one and if not the
3rd one leftover is.

Is This Answer Correct ?    20 Yes 2 No

You have 8 balls. One of them is defective and weighs less than others. You have a balance to measu..

Answer / abi

Firstly we take 6 balls, placing 3 on each pan of the
balance & check which pan goes up(1st weighing). If no
change it means the balls don't contain the defective
one,therefore the other two contain the defective
ball,which can be found out easily(2nd weighing).
Now if one of the pan goes up,it means it contains the
defective ball(out of 3 balls).We select these 3 & unload
the pans. Now we keep any of the 2 balls(from the selected
balls)on either side of the balance & weigh(2nd weighing).
One of these two will be the defective one and if not the
3rd one leftover is.

Is This Answer Correct ?    8 Yes 1 No

You have 8 balls. One of them is defective and weighs less than others. You have a balance to measu..

Answer / aby

Firstly we take 4 balls, placing 2 on each pan of the
balance & check which pan goes up(1st weighing). If no
change it means the balls don't contain the defective
one,therefore the other Group of 4 balls contain the
defective
ball,Now if one of the pan goes up,it means it contains the
defective ball(out of 2 balls).We select these 2 & unload
the pans. Now we keep 1 ball(from the selected
balls)on either side of the balance & weigh(2nd weighing).
One of these two will be the defective one otherwise it
must b in the second group of balls.

Is This Answer Correct ?    3 Yes 11 No

You have 8 balls. One of them is defective and weighs less than others. You have a balance to measu..

Answer / rajeev kumar

Solution:

a. first take 4-4 group of balls and weight this. Then one
of group will be less.
b. next we take less weight group and take 2-2 group and
weight this and choose less weight group.
c. next take 1-1 group and weight choose less weight group.
and there is one ball.
So this ball is defective ball.

Is This Answer Correct ?    6 Yes 25 No

Post New Answer

More General Aptitude Interview Questions

Tis known in refined company, that choosing K things out of N can be done in ways as many as choosing N minus K from N: I pick K, you the remaining. This simply states the binomial coefficient identity . Find though a cooler bijection, where you show a knack uncanny, of making your choices contain all K of mine.For pedantry let K be no more than half N.

0 Answers   Google, Parrot Systems,

If ABC =C3C3 and CAB = D3D3, Then find D3÷B3D3÷B3

0 Answers   Infosys,

A car is traveling at a uniform speed. The driver sees a milestone showing a 2-digit number. After traveling for an hour the driver sees another milestone with the same digits in reverse order. After another hour the driver sees another milestone containing the same two digits. What is the average speed of the driver.

0 Answers   Infosys,

7. A new medicine has been developed and its effectiveness has been determined by carrying out an experimental study. 30 patients were divided into groups of 20 and 10. The group having 20, were given medicine while the other group dint get any medication. The results obtained where as follows:- Medication Non-medication Improved 8 2 Unimproved 12 8 Based on data, I think medication was:-

2 Answers  

Ben can have a piece of work done in 8 days, Joe can work three times faster than the Ben, Ram can work five times faster than Ben. How many days will they take to do the work together ?

3 Answers  




Find the next series: AD DP PL LV ?

0 Answers   CTS,

If m-4 is 7 more than n then m+9 is how much more than n+2

0 Answers   Changepond,

A clock showing 6 o'clock takes 30 secs to strike 6 times.How long will it take to strike 12 at midnight?

0 Answers   Infosys,

I have sample questions for QUANTITATIVE APTITUDE for bank test. Those who want this can contact me : beenasbi@gmail.com

96 Answers   ADB, Banking, FCMB, Infosys, ISRO, Soneri Bank, UCO Bank,

A boy asked a girl her name she replied your name is behind your scooty Behind the scooty is written 7.3 3.3 9.3 2.3 What is her name? ?

3 Answers   HP,

send me sbi previous clerical examinatiom question with answer o my email id alongwith sample question with answer

0 Answers  

The number 0.05 is what percent of 20?

0 Answers   Axis Bank,

For more General Aptitude Interview Questions Click Here
Categories