Problem number 12. The five balls shown begin to move simultaneously in the directions indicated by their arrows. When two balls going in opposite directions collide, the bigger ball swallows up the smaller one and increases its value by the value of the smaller ball. The bigger ball continues to move in its original direction, as shown in the following example. What is the final result of the collisions of the five balls shown? A, 50 going to the right, B, 48 going to the right, C, 49 going to the left, D, 50 going to the left, or E, 49 going to the right. The problem says that the balls are moving simultaneously or at the same time. Also, note that this set of balls is moving in one direction and this set of balls is moving in the other direction. They will only bump into each other or collide where a ball going to the right meets a ball going to the left. Here's a close-up of just the balls. The first balls to collide are the one with the 9 and the one with the 3. 9 plus 3 is 12, and because the ball of the 9 was bigger, this ball will continue going to the right. Now, this ball collides with the ball of the 7. 7 plus 12 is 19. The ball of the 12 is bigger, so it continues going this way. Now, the ball of the 19 collides with the ball of the 20. 19 plus 20 is 39, and because the 20 was bigger, this ball is going to the left. All that's left now is the ball of the 10 and the ball of the 39. 10 plus 39 is 49, and 39 was bigger, so the direction is to the left. So, we're left with a ball of a value of 49 going towards the left. And there isn't a problem. This is answer C.

collision

absorption

ball values

direction change

final result