Total number of outcomes = 6 × 6 = 36
(i)Total number of outcomes when 5 comes up on either time are (5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5, 6), (1, 5), (2, 5), (3, 5), (4, 5), (6, 5)
Hence, total number of favourable cases = 11
P (5 will come up either time)
=
11
36
P (5 will not come up either time)
=
1
−
11
36
=
25
36
(ii)Total outcomes when 5 comes exactly one time are (5, 1), (5, 2), (5, 3), (5, 4), (5, 6), (1, 5), (2, 5), (3, 5), (4, 5), (6, 5)
No. of possible outcomes = 10
So, probability =
10
36
=
5
18
(iii) The only possibility when 5 comes both the times is (5,5).
So, its probability =
1
36
Q.
Two dice are rolled once. Find the probability of getting such numbers on two dice whose product is a perfect square.
Solution:
On throwing 2 dice the total number of outcomes is 36.
Out of these 36 outcomes we need to find the probability of getting the product of two numbers on the dices is a perfect square
Such outcomes are as shown:
(1, 1), (1, 4), (2, 2), (3, 3), (4, 1), (4, 4), (5, 5), (6, 6)
Number of favorable outcomes = 8
Probability of getting the numbers whose product is a perfect square on the dice = 8 / 36
= 2 / 9
Q.
A letter is chosen at random from the letters of the word 'ASSOCIATION'. Find the probability that the chosen letter is a (i) vowel (ii) consonant (iii) an S.
Solution:
Number of letters in the given word =11
total number of vowels =6
Total number of consonants =5
No. of the letter 'S' = 2
so
(i) probability of getting a vowel =

(ii)probability of getting a consonent =

(iii)probability of letter chosen S=
Q.
Five cards - the ten, jack, queen, king and ace of diamonds are well shuffled with their faces downwards. One card si then picked up at random. (a) What is the probability that the drawn card is the queen?
(b) If the queen is drawn and put aside and a second card is drawn, find the probability that the second card is (i) an ace, (ii) a queen.
Solution:
(a) No. of cards = 5
No. of queen=1
So, probability = 1/5
(b) If the queen is drawn and put aside and a second card is drawn, total no. of cards = 5-1 = 4
(i) No. of ace =1
It's probability = 1/4
(ii) No. of queen = 0
Its probability = 0
Q.
What is the probability that an ordinary year has 53 Mondays?
Solution:
In a year there are 365 days that is, 52 weeks and 1 day
Hence, there will be 52 Mondays for sure.
52 weeks = 364 days
365 – 364 = 1 day
So, in an ordinary year (that is
not
a Leap year),
there will be 52 Mondays and 1 day will be left.
This that one day could be a
Monday or a Tuesday or a Wednesday or a Thursday or a Friday or a Saturday or a Sunday.
Of these total 7 outcomes, the favourable outcome is 1
(which is MONDAY)
.
Hence, the probability of getting 53 Mondays =
Q.
In a lottery, there are 8 prizes and 16 blanks. What is the probability of getting a prize?
(a)
1
2
(b)
1
3
(c)
2
3
(d) None of these
Solution:
(b) 1/3
total events= 8+16=24
favourable events=8
required
probabilty=8/24=1/3
Benefits of RS Aggarwal Solutions for Class 10 Maths Chapter 15 Exercise 15.2
-
Clear Explanations:
Each solution is explained in simple steps making it easy for students to understand the methods used to solve probability problems.
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Expert Guidance:
The solutions are prepared by subject experts ensuring accurate and reliable answers.
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Exam Preparation:
Practicing these solutions helps students prepare effectively for their board exams by strengthening their understanding of probability concepts.
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Conceptual Clarity:
The detailed solutions help students grasp the fundamental concepts of probability, which is crucial for solving more complex problems.
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Confidence Building:
By working through these problems, students can build their confidence in handling probability questions in exams.