Jar Q contains 12 balls, and Jar R contains 8 balls. The probability of drawing a yellow
ball at random from Jar Q is 1/3. The probability of drawing a yellow ball at random from Jar R is 3/4. All the balls are poured into an empty jar, Jar S. What is the probability of drawing a yellow ball at
random from Jar S?
A. 1/4
B. 1/3
C. 1/2
D. 4/7