# Quantitative Aptitude: Probability Questions – Set 15

1. A carton contains 21 balls numbered 1 to 21. A ball is drawn and then another ball is drawn without replacement. What is the probability that both balls are even numbered?
3/14
2/7
4/14
5/16
None of these
Option A
Required probability = 10/21 * 9/20

2. There are 3 grey, 4 olive and 5 white color balls in a bag. If a ball is picked at random, what is the probability of having either a grey or a white ball?
1/2
2/3
3/4
4/9
None of these
Option B
P(E1 or E2) = P(E1) + P(E2)
=1/4 + 5/ 12

3. A carton contains pieces with numbers from 1 to 50 written on them. A piece is drawn and replaced. Then another piece is drawn and after replacing another piece is drawn. What is the probability that an even number appears on the first draw, an odd number on the second draw and a number divisible by 3 on the third draw?
4/25
1/25
2/25
Cannot be determined
None of these
Option C
So, the probability of all the events taking place is:
1/2 * 1/2 * 16/50

4. When 4 fair coins are tossed togethe what is probability of getting at least 3 heads?
5/16
3/4
7/13
10/14
None of these
Option A

5. A committee of 3 members is to be made out of 6 boys and 5 girls. What is the probability that the committee has at least two girls?
14/33
10/32
15/31
17/35
None of these
Option A
Total possibe outcomes=11C3

6. There are 15 males and 10 female in a class. If three candidates are selected at random, what is the probability that 1 female and 2 males are selected?
20/34
21/46
31/39
21/47
None of these
Option B
Probability=(15C2 * 10C1) /25C3

7. Three dice are thrown togeth. Find the probability of getting total of at least 6 ?
103/108
105/109
101/105
114/117
None of these
Option A

8. A bag contains 6 pale and 5 yale balls. One ball is drawn randomly. What is the probability that the ball drawn is Pale color?
4/11
5/11
7/11
6/11
8/11
Option D
Probability=6C1/11C1

9. In a carton there are 10 mangoes and 2/5th of the mangoes are rotten. If three mangoes are taken out from the carton, what will be the probability that at least one mango is rotten?
5/6
4/5
7/9
11/13
None of these
Option A

10. A bag contains 5 yale and 2 grey and 3 ruby colour dice. If one dice from the bag are chosen at random, what is the probability that dice is either yale or ruby colour?
4/5
5/9
10/13
14/15
None of these
Option A
Total outcomes=(5C1/10C1) + (3C1 /10C1)