Question

Nine balls are given .All are equally weighed except one that was less weighed .How would we identify the less weighed in two chances?
Help me

Answer 1

Answer:

Step-by-step explanation:

Let's divide them in three groups say A, B and C.

Now we have three groups each comprising 3 balls say,

A1,A2,A3,  B1,B2,B3,  C1,C2,C3

Now weigh A against B

Case1: A=B

In this case the defective ball is one from lot C.

Weigh C1 against C2

If C1>C2

C2 is lighter.

Ans C2.

If C1C1 is lighter.

Ans C1.

If C1=C2

C3 is the answer.

Case2: A>B

Here B is the lighter lot hence one of them is defective.

Now weigh B1 against B2

If B1>B2

B2 is lighter hence the answer.

If B2>B1

B1 is lighter.

Ans B1.

If B1=B2

B3 is the defective one.

Case3: AIn this case the defective ball is from lot A.

We can find out which one similarly as in above two cases.

Hope this helps