Exams › IBPS PO › Quantitative Aptitude
In a bag, there are 3 magenta balls, 5 green balls, and 7 blue balls. Two balls are drawn one by one without replacement. If the first ball drawn is magenta, then 8 more magenta balls are added to the bag. Find the probability that both balls drawn are magenta.
- 1/35
- 2/11
- 1/11
- 1/23
Correct answer: 1/11
Solution
The probability of drawing a magenta ball first is \(3/15 = 1/5\). After that ball is removed and 8 magenta balls are added, the bag has 10 magenta balls out of 22 total balls, so the second magenta probability is \(10/22 = 5/11\). Multiplying gives \(1/5 \times 5/11 = 1/11\).
Related IBPS PO Quantitative Aptitude questions
- Q84. A box contains 4 red balls, 6 white balls, 2 orange balls, and 8 black balls. Quantity I: Two balls are drawn at random. Probability that both are either red or white. Quantity II: Three balls are drawn. Probability that all are different.
- Directions (71-72): Given below is the number of male and female students in classes A, B and C. Some data are missing, which you have to calculate as per the instructions provided. Class A | Class B | Class C Boys: 50 | -- | -- Girls: -- | 80 | 60 Note: (i) The probability of selecting a boy from class A is \(\frac{5}{12}\). (ii) The probability of selecting a boy from all the boys of all classes is \(\frac{14}{19}\), such that the boy selected is either from class B or class C. (iii) The probability of selecting a boy from class B is equal to the probability of selecting a boy from class C. How many boys are there in class C?
- A bag contains some green balls, some blue balls, and seven red balls. The probability of picking one green ball is \(\frac{1}{7}\) more than that of picking one red ball from the bag, and the probability of picking one blue ball is \(\frac{9}{35}\) more than that of picking one red ball from the bag. Find the total number of blue balls in the bag.
- Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?
- A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
- In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
⚔️ Practice IBPS PO Quantitative Aptitude free + battle 1v1 →