1. (1) A dice is thrown once. Find the probability of getting
(a) A number greater than 3
(b) A number less than 5
A. ½,2/3, 4/3, 2/3
B. 2/3, 4/3, 2/3
C. 4/3, 4/3, 2/3
D. 4/3, 2/3,13/8
2. A bag contain 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is
(a) Red
(b) Black or white
(c) Not black
A. 7/15
B. 8/15
C. 2/3
D. 4/3
3. A bag contains 4 red 5 black and 6 white balls. A ball is drawn from the bag a random. Find the probability that the ball drawn is
(a) White
(b) Red
(c) Not black
(d) Red or white
A. 2/5, 4/15, 2/3, 2/3
B. 4/3, 4/15, 1/3, 2/3
C. 4/15, 2/3, 2/3 1/3
D. 4/15, 2/3, 4/3 2/3
4. A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither a queen nor a jack.
A. 11/13
B. 12/13
C. 11/14
D. 11/12
5. Tickets numbered from 1 to 20 are mixed up together and then a ticket is drawn at random. What is the probability that the ticket has a number which is a multiple of 3 or 7?
A. 2/5
B. 2/3
C. 4/3
D. 2/3
6. In a single throw of dice, what is the probability of
(a) An odd number on one dice and 6 on the other
(b) A number greater than 4 on each dice
(c) A total of 11
(d) Getting same number on either dice.
A. 1/6, 1/9, 1/18, 1/6
B. 1/6, 1/9, 2/18, 1/6
C. 1/6, 1/3, 1/18, 1/6
D. 1/6, 1/9, 7/18, 1/6
7. A die is thrown twice. Find the probability of getting
(a) doublets
(b) number greater than 5 on one dice.
A. 1/6, 11/36
B. 1/6, 11/7
C. 1/6, 11/6
D. 1/6, 11/3
8. Three coins are tossed simultaneously. Find the probability of getting
(a) Exactly 2 heads
(b) No heads
A. 2/8, 1/8
B. 3/8, 1/8
C. 3/8, 7/8
D. 4/3, 1/8
9. In a simultaneous toss of four coins, What is the probability of getting:
(a) Less than 2 heads?
(b) Exactly 3 head
(c) More than 2 heads?
A. 5/6, 2/8, 5/16
B. 5/6, 3/8, 5/16
C. 5/6, 3/9, 5/16
D. 5/6, 3/4, 5/1
10. Three coins are tossed once. Find the probability of:
(a) 3 heads
(b) exactly 2 heads
(c) at least two heads
A. 1/3, 3/8, 1/2
B. 1/8, 3/8, 1/9
C. 1/8, 3/8, 1/2
D. 1/8, 3/7, ½
11. A bag contains 5 red balls, 8 White balls, 4 green balls and 7 black balls. A ball is drawn at random from the bag. Fine the probability that it is. (i) Black (ii) not green.
A. 2/3
B. 5/6
C. 3/8
D. 7/3
12. A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither an ace nor a king.
A. 2/3
B. 11/13
C. 3/8
D. 7/3
13. An unbiased dice is tossed.
1. Write the sample space of the experiment
2. Find the probability of getting a number greater than 4.
3. Find the probability of getting a prime number.
A. 6,2,2/3
B. 6,2,1/2
C. 6,2,2/3
D. 6,2,2/7
14. Out of 400 bulbs in a box, 15 bulbs a defective. One ball is taken out at random from the box. Find the probability that the drawn bulb is not defective.
A. 77/80
B. 77/80
C. 77/80
D. 77/80
15. Find the probability of getting 53 Fridays in a leap year.
a. 1/7
b. 2/7
c. 3/7
d. 4/7
16. Three unbiased coins are tossed simultaneously. What is the probability of getting exactly two heads?
e. 3/8
f. 4/8
g. 3/7
h. 4/7
17. A dice is thrown twice. Find the probability of getting (a) doublets (b) prime number on each die.
i. 3/8
j. 1/4
k. 3/4
l. 2/4
18 One card is drawn from a well shuffled pack of 52 cards. Find the probability of drawing.
(i) an ace (ii) 2 of spades (iii) 10 of black suit (iv)a king of hearts
m. 1/13,1/13,1/13,1/13
n. 1/13,2/13,1/13,1/13
o. 1/13,1/13,3/13,1/13
p. 1/13,1/13,1/13,4/13
19. One card is drawn from a well shuffled deck of 52 cards calculate the probability that the card will
a) not be an ace
b) be an ace
q. 12/13,1/13
r. 2/13,1/13
s. 2/26,1/13
t. 2/13,1/52
20. Find the probability of getting Monday or Tuesday in a leap year.
u. 1/2
v. 2/7
w. 1/7
x. 2/14
21. From a group of 3 boys and 5 girls, a child is to be selected for the competition. Find the probability that the selected child is ( i ) a boy ( ii ) a girl.
y. 3/8,5/8
z. 3/5,8/3
aa. 8/5,4/3
bb. 1/13,1/13
22. In a single throw of two dice , find the probability of getting
i) Two heads ii) At least one heads
cc. ¼,3/4
dd. 2/4,3/4
ee. ¼,1/2
ff. ¾,3/4
- What is probability of choosing the red ball from a box containing 20 balls if it is having equal number of yellow, red, blue and green balls?
gg. 5/20
hh. ¼
ii. ½
jj. 1/4
24. There are three children in a family. Find the probability that there is one girl in the family.
kk. 1/3
ll. ¼
mm. ½
nn. 1
- One card is drawn from a well shuffled deck of 52 cards. Calculate the probability that the card drawn will be an ace.
- 1/13
- 4/13
- 13/52
- 13/52
Answers
1. 1/2, 2/3, | 2. 7/15, 8/15, 2/3 | 3. 2/5, 4/15, 2/3, 2/3 | 4. 11/13, |
5. 2/5 | 6. 1/6, 1/9, 1/18, 1/6 | 7. 1/6, 11/36 | 8. 3/8, 1/8 |
9. 5/6, 3/8, 5/16 | 10. 1/8, 3/8, 1/2 | 11. 5/6 | 12. 11/13 |
13. 6,2,1/2 | 14. 77/80 | 15. 2/7 | 16. 3/8 |
17.1/13,1/13,1/13,1/13 | 18.1/13,1/13,1/13,1/13 | 19. 2/13,1/13 | 20.2/7 |
21.1/4,3/4 | 221/4,3/4 | 231/4 | 24 |
25.1/13 11. An unbiased dice is tossed. 26. Write the sample space of the experiment 27. Find the probability of getting a number greater than 4. 28. Find the probability of getting a prime number. Solution:-
n(s) = 6 2. E = event of getting a number greater than 4 n (E) = 2 P (> 4) = Probability of a number greater than 4 3. E = Event of getting a prime number n (E) = 3
12. Out of 400 bulbs in a box, 15 bulbs a defective. One ball is taken out at random from the box. Find the probability that the drawn bulb is not defective. Solution:- Total number of bulbs = 400 Total number of defective bulb = 15 Total number of non-defective bulbs = 400-15 = 385 P (not defective bulb) = 385/400 = 77/80 13. Find the probability of getting 53 Fridays in a leap year. Solution:- No. of days in a leap year = 366 366 days = 52 weeks and 2 days. A leap year must has 52 Fridays The remaining two days can be (a) Sunday an Monday Out of 7 case, 2 cases have Friday P (53 Friday) = 2/7
14. Three unbiased coins are tossed simultaneously. What is the probability of getting exactly two heads? Solution: - When three coins are tossed simultaneously, the sample space is S = {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}. n(S) = 8 E = Set of cases favorable to the event = {HHT, HTH, THH} n(E) = 3 P (exactly two heads) = 15.. A dice is thrown twice. Find the probability of getting (a) doublets (b) prime number on each die. Solutions: - Sample space = S = { (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6) (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) } n (S) = 36 (i) E = Events getting doublet = {(1, 1) (2, 2) (3, 3) (4, 4) (5, 5) (6, 6)} n (E) = 6 P(doublet) = (ii) E = Events getting prime number on each die. = {(2, 2), (2, 3), (2, 5), (3, 2), (3, 3), (3, 5), (5, 2), (5, 3), (5, 5)} n(E) = 9 P (getting prime number on each die) = n(E)/n(S) = 9/36 = 1/4
16. A bag contains 5 red balls, 8 White balls, 4 green balls and 7 black balls. A ball is drawn at random from the bag. Fine the probability that it is. (i) Black (ii) not green. Solution:- Red balls = 5 White balls = 8 Green balls = 4 Black balls = 7 (i) P (Black balls) = 7/24 17. A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither an ace nor a king. Solution:- P (neither an ace nor a king) = 1 – p (either an ace or a king) = 1 – 8/52 {no. of ace = 4} = (52 – 8)/52 = 44/52 = 11/13
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