In a bag there are a certain number of black balls and blue balls. The probability of picking up exactly 1 blue ball when 2 balls are randomly drawn, is 1/2. Which of the following is the ratio of the number of black balls to blue balls in the bag  Select the correct option
A) 1:2	B) 1:4	C) 1:1	D) 1:5	E) 1:6
since the probability of drawing a blue ball out of two picks is 1/2.   the ratio of the blue ball to black balls should be 1:1   Answer : 1:1
<result>C</result>
In a bag there are a certain number of black balls and blue balls. The probability of picking up exactly 1 blue ball when 2 balls are randomly drawn, is 1/2. Which of the following is the ratio of the number of black balls to blue balls in the bag