<p>To calculate the probability of drawing a blue ball from the box, we need to determine the ratio of the number of blue balls to the total number of balls in the box.</p><p>In this case, the box contains 20 blue balls and 10 red balls, giving us a total of 30 balls.</p><p>Therefore, the probability of drawing a blue ball is calculated as:</p><p>Probability of drawing a blue ball = Number of blue balls / Total number of balls</p><p>Probability of drawing a blue ball = 20 / 30</p><p>Simplifying the fraction, we get:</p><p>Probability of drawing a blue ball = 2 / 3</p><p>So, the probability of randomly selecting a blue ball from the box is 2/3 or approximately 0.6667.</p>