Answer

However the actual answer is two weighings. The technique is to split the balls into three approximately equal groups, here we have 3,3,2. Then weigh the 3,3 groups against each other, if they are the same, then weigh the two remaining balls against one another. If one of the two 3,3 groups are heavier, then select that group and weigh any of the two balls against one another, if one is heavy, then you got the ball, if both are equal, then the third one of the group is the heavier.

Decision Tree

Here is a schematic diagram:

Good job sir..............u hv guessd it rite.