Question

NOBODY CAN ANSWER THIS EXCEPT SMART ONE[please answer its very very urgent] There are 9 balls in which 8 balls are of same weight but 1 ball weight is less than them. You have weighing scale which u can use just 2 time . Then how will you know that which one is having less weight among them.[ Weighing scale is of rope]

Answer 1

Divide the 9 balls into 3 groups of 3. Compare the weight of two of those groups. 

The heavier group should then be obvious, it will either tip the scales, or, if the scales stay balanced, then it is the group you did include.

Now, choose 2 balls from this group and compare their weights, and using the same logic as before, the lighter ball will be obvious.

Answer 2

Hey here is your answer
As there are 8 balls of same weight and one of half the weight of those 8 balls
So see we will take all the balls and keep them on the weighing scale
we will get a weight in point 8.5
now one by one we will keep all the balls on the weighing scale as the weight comes in point by keeping any ball we will take that ball and we will know that the ball is half the weight of of the other eight balls .
Keep smiling!