A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball is double that of a red ball. Determine the number of blue balls in the bag?
A5
B10
C8
D15
Answer:
B. 10
Read Explanation:
Number of red ball = 5
Number of blue ball = X
Total = 5 + x
P{getting red} = 5/(5 + X)
P{getting blue} = X/(5+X)
X/(5 + X) = 2 × 5/(5 + X)
On solving
X = 10
Number of blue balls in the bag = 10
