Probability Quiz Set 012 | Maths Aptitude Quiz Questions and Mock Test on Probability Set 12 | mock tests for Bank PO, SSC Exams, SO Clerical Exam, GATE Exam, LIC AO, GIC AO, etc.

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Question 1

48 defective pens are accidentally mixed with 56 good ones. It is not possible to just look at a pen and tell whether it is defective or not. One pen is taken out at random. What is the probability that it is a defective pen?

${6/13}$.

$50/104$.

$7/104$.

$11/104$.

Soln.
Ans: a

Out of the total number of pens = 104, the chances favoring defective pen are 48. So the probability is 48/104 = ${6/13}$.

Solution | Discuss! | Chapters»

Question 2

9 tumblers are lying inverted on a table. 7 of them contain balls, but 2 of them are empty. What is the probability of getting a ball if one of the tumblers is opened randomly?

${7/9}$.

$8/9$.

$9/9$.

$12/9$.

Soln.
Ans: a

Chances favoring a ball are 7, whereas the total chances are 9. The probability is 7/9 = ${7/9}$.

Solution | Discuss! | Chapters»

Question 3

A bag contains 2 Red, 4 Blue and 7 Green marbles. What is the probability of drawing a Red marble if 2 marbles are drawn out randomly?

${23/78}$.

$7/13$.

$24/78$.

$28/78$.

Soln.
Ans: a

Total number of marbles is 13. Combinations of 2 marbles that are possible = ¹³C₂ = ${13 × 12}/2$ = 78. If one of the two balls is red, then red + red is one possibility, and 2 × (4 + 7) are the other possibilities. So total favorable outcomes = 1 + 2 × 11 = 23, and the probability is 23/78 = ${23/78}$.

Solution | Discuss! | Chapters»

Question 4

Karmjeet and Sham are friends. What is the probability that both will have different birthdays, ignoring a leap year?

${364/365}$.

$21/365$.

$365/365$.

$369/365$.

Soln.
Ans: a

The birthday of second friend has 365 outcomes. If it is not to match the birthday of the first friend, the number of favorable outcomes is 365 - 1 = 364. So probability is 364/365.

Solution | Discuss! | Chapters»

Question 5

A box contains 5 pink, 2 maroon and 6 cyan balls. What is the probability of drawing a ball that is neither maroon nor pink?

${6/13}$.

$7/13$.

$7/78$.

$11/78$.

Soln.
Ans: a

Total number of marbles is 13. We have to basically find the probability of picking a cyan ball, for which 6 chances are favorable. So probability = 6/13 = ${6/13}$.

Solution | Discuss! | Chapters»