A bag containing 8 red balls and some green balls. if the probability of drawing is half that of a green ball, find the number of green balls in the bag.
Answers
The complete question is : A bag containing 8 red balls and some green balls. If the probability of drawing a red ball is half that of a green ball, find the number of green balls in the bag.
The number of green balls in the bag is 16.
• Let the number of green balls in the bag be x.
Given that the number of red balls in the bag = 8
∴ Total number of balls = x + 8
• Probability of drawing a red ball from the bag = 8 / (8 + x)
Probability of drawing a green ball from the bag = x / (8 + x)
• According to the question,
8 / (8 +x) = (1 / 2) × { (x / (8 + x) }
=> 8 / (8 +x) = x / { 2 (8 + x) }
On cross-multiplying,
8 × 2 = x (8 + x) / (8 + x)
=> 16 = x
Or, x = 16
• Therefore, the number of green balls in the bag = 16.
Answer:
the 1st answer is correct I also loved his formula