Let's analyze the image:

• We have a scale with three sides.
• On one side, there are two white balls and one red ball.
• On another side, there are three red balls.
• On the third side, there is a number 30.

We need to figure out the value of a white ball.

Let's assign variables:

• White ball = W
• Red ball = R

From the image, we can set up the following equations:

1. 2W + R = 3R (since the first two sides balance)
2. 3R = 30 (since the second and third sides balance)

From equation 2, we get: R = 10

Substituting R = 10 in equation 1, we get: 2W + 10 = 3 * 10 2W = 20 W = 10

Therefore, the value of a white ball is 10.