In a container, there are 6 red marbles, blue marbles are 40% more than red marbles and green marbles are 25% less than blue marbles. Two marbles are drawn without replacement. If the first marble comes out to be green, then 50% of the red marbles are taken out of the container. (Approximating marbles to nearest whole number) Find the probability that first marble is green and second is red?
In a container, there are 6 red marbles, blue marbles are 40% more than red marbles and green marbles are 25% less than blue marbles. Two marbles are drawn without replacement. If the first marble comes out to be green, then 50% of the red marbles are taken out of the container. (Approximating marbles to nearest whole number) Find the probability that first marble is green and second is red? Correct Answer 9/160
Red Marbles = 6
∵ Blue Marbles are 40% more than red marbles
⇒ Blue Marbles = 6 × 1.4 = 8.4 ≈ 8
∵ Green Marbles are 25% less than blue marbles
⇒ Green Marbles = 8 × 0.75 = 6
Total Marbles = 6 + 8 + 6 = 20
Probability of drawing first green marble = 6C1/20C1 = 6/20 = 3/10
As per question, now 50% of the red marbles are taken out
⇒ Red Marbles = 6 × 0.5 = 3
∵ 1 green marble is already drawn out, so only 5 green balls are left
Total Marbles Left = 3 + 8 + 5 = 16
Probability of Drawing second ball that is red = 3C1/16C1 = 3/16
P(first ball is green and second is red) = (3/10) × (3/16)
∴ Probability = 9/160