Bissoy.com
Doctors Medicines MCQs Q&A

A bag contains 8 red balls and 12 blue balls. One ball Is drawn at random and replaced with 5 green balls. A second ball is drawn without replacement. What Is the probability that the first ball drawn is red in colour and the second ball drawn is blue in colour?

A bag contains 8 red balls and 12 blue balls. One ball Is drawn at random and replaced with 5 green balls. A second ball is drawn without replacement. What Is the probability that the first ball drawn is red in colour and the second ball drawn is blue in colour? Correct Answer 1/5

Given:

A bag contains 8 red balls and 12 blue balls

One ball Is drawn at random and replaced with 5 green balls. A second ball was drawn without replacement.

Calculation:

Probability of getting 1st ball as red = 8/(8 + 12) = 8/20

Probability of getting 2nd ball as blue = 12/(8 + 12 + 5 – 1) = 12/24

∴ Required probability = 8/20 × 12/24 = 1/5

Related Questions

Compare the values of the two quantities in the question and answer. Quantity 1: A bag contains 20 balls which are red, green and blue. Find the number of red balls in the bag, if the probability of picking a blue ball is 2/5 and that of either a red or a blue ball is 3/4. Quantity 2: A bag contains 25 balls which are red, green and blue. The probability of picking a red ball first is 2/5. If the first ball was red and without keeping it back, probability of picking a blue ball is 1/3, find the number of green balls.
The following question, there are three statements I, II and III. Read the question carefully and mark your answer according to which statements(s) is/are sufficient to the answer the question. Find the probability that both the balls are of blue color. Statement I: In a bag containing 4 red balls, 6 blue balls and 8 yellow balls, two balls are drawn at random one by one without replacement. Statement II: First ball is blue and if this happens then 5 more blue balls are added in the bag Statement III: Total blue balls are twice more than the other balls at the end of the drawing of balls
A bag contains 8 red balls and 12 blue balls. One ball Is drawn at random and replaced with 5 green balls. A second ball was drawn without replacement. What Is the probability that first ball drawn is red In colour and the second ball drawn Is blue in colour?
Ashutosh has a box containing 8 identical red balls, 9 identical blue balls and 10 identical green balls. He is required to distribute all these balls into three bags A, B and C such that the total number of balls in bag A is more than that in bag B, which, in turn, is more than that in bag C. Moreover, he needs to ensure that the number or red balls in bag A is more than that in bag B which in turn is more than that in bag C, and similarly for the blue and green balls. In how many ways can he do this? Each bag must contain at least one ball of each type.
A bag contains 4 red balls, 6 blue balls and 8 pink balls. One ball is drawn at random and replace with 3 pink balls. A second ball was drawn without replacement. What is the probability that the first ball drawn was either red or blue in colour and the second ball drawn was pink in colour? 
Bag A contains certain number of balls (red and green). Bag B has 60% more red balls than in bag A and 10% more green balls than in bag A. If the ratio of total balls in bag A to that in bag B is 10 : 13, then what is the ratio of red to the green balls in bag B?
In a bag which contains 40 balls, there are 18 red balls and some green and blue balls. If two balls are picked up from the bag without replacement, then the probability of the first ball being red and second being green is 3/26. Find the number of blue balls in the bag.
A bag contains 4 red balls, 6 blue balls and 8 pink balls. One ball is drawn at random and replaced with 3 pink balls. A probability that the first ball drawn was either red or blue in colour and the second drawn was pink in colour ?
A box contains 50 balls, in which 5 are red balls, 6 are green balls, 9 are blue balls, and the remaining are yellow balls. Quantity I: Probability of picking 2 balls such that one is green and the other one is blue Quantity II: Probability of picking 3 balls such that at least one of them is red Quantity III: Probability of picking 3 balls such that at least one of them is blue
A box contains red, green and blue colored balls. When one ball is drawn randomly from the box, the probability that it is either green or blue is 2/3. Also, the probability that the ball drawn randomly from the box is either red or green is 3/5. When two balls are drawn one after another from the box, the probability that both balls are of green color is 1/15. Find the total number of balls in the box.