Lowest weighed ball

Q1. There are total of 10 balls , out of that 9 were of same weight and 1 is off diff weight, find that ball using minimum measurement?

Ans:
Divide balls into group of 3,3,3,1

Weight the first 2 groups of 3 balls if they are equal then they don't have the ball the group with lowest weight has the ball

Now we have 4 ball's left weigh them by dividing them into 2 groups of 2 balls. The group with lowest weight has the ball

Now weigh 2 ball's with each other and you will have ball with lowest weight.