Answer:
The magician can use any number of black and white balls for the magic trick. The balls will be placed in a bag, and the magician will perform the trick using these balls.
One example of a magic trick that can be done with the black and white balls is the "color change" trick. The magician can start by placing some black balls and white balls in the bag. Then, she can reach into the bag and pull out a ball. If she pulls out a black ball, she can show it to the audience and then place it back into the bag. However, when she pulls out the ball again, it has magically changed color and become white! This can be repeated with different balls and different colors to create a visually stunning trick.
Another example is the "vanishing ball" trick. In this trick, the magician can start by showing the audience an empty bag. Then, she can place some black balls and white balls into the bag. After giving the bag a magical wave or saying a magic word, the magician can turn the bag inside out or show it empty, and all the balls have vanished! This trick can be done by using a special bag with a hidden compartment or by using sleight of hand techniques to make the balls disappear.
The number of black and white balls used in these tricks can vary depending on the magician's preference and the specific trick being performed. The magician can choose to use an equal number of black and white balls for a balanced effect, or she can use more of one color to create a specific pattern or illusion.
Overall, the number of black and white balls used in a magic trick is determined by the magician's creativity and the specific trick being performed. The balls are an essential element in creating the mystery and illusion that captivates the audience's attention.