Groupon Interview Question: you have 8 balls. one ball we... | Glassdoor

Interview Question

Data Analyst Interview Chennai (India)

you have 8 balls. one ball weighs 1.2kg rest each weighs

  1kg. you need to do 2 measurements only. how will find that 1.2kg ball.

Interview Answer

2 Answers


first take 6 balls. weigh them in 3,3. if same weight it should balance and the rest 2 should have a 1.2 kg.
if 3,3 not same take 2 balls from the heavier side and take measurement.

Interview Candidate on Jul 14, 2013

Arrange all 8 balls in a line. Take the sum like this: weight(ball1) + 2*weight(ball2) + 3*weight(ball3) + 4*weight(ball4) +... + 8*weight(ball8) = 8.(position of ball with 1.1kg weight). Decimal part will be the position of ball.

Abhay on Jun 23, 2018

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